I bought it a couple hours ago and I've been playing it on and off between classes. I like it! The lock-on attack works way better than I thought it would, and the game plays reasonably well. 
 
Thoughts...?

Not as good as the sonic advance games or sonic rush on ds. But ok.

The game is way better than I thought it would be to be honest....however, there are a few annoying sections in the game just like any Sonic game. Two that come to mind are the card bridges in the second zone and that bloody torch puzzle in Zone 3 lol
 
But yeah, I am enjoying the experience.

I only played the first level because that's all they give you in the demo but the feel of controls feel so weird to me and I don't like them at all. I was expecting it to control like the genesis sonic games. I don't see the point of the lock on mechanic in a 2D game feel like too much hand holding to me. I'm happy they kept the spin dash that was added in Sonic 2 since I thought they said the controls were going to be modeled after Sonic 1 but maybe I read wrong or that change somewhere along the way. 
 
Regardless they screwed up on the pricing. it should have been 10 dollars and thats what i'll pay when it has a deal or week.

It's okay, but what the hell happened to Sonic's momentum?  I mean, it probably controls better than the old games but it just felt weird that he stops mid air if you stop pushing the direction.  Something to get used to I suppose.

Compared to the Genesis games, this Sonic feels lethargic.

Whoever designed some of these special stages deserves a savage beating.

Sonic 4 is basically levels from sonic 1 and 2 with sonic 3 sound effects. Hell, the first 2 levels are Green Hill zone with sonic 1 first stage boss and stage 2 is basically the casino zone ripped right from sonic 2 and even has the exact same boss fight in it. If they were going to slap on a game that says sonic 4, at least make the same concept as the first 3 games but i dunno make something new? or at least make the boss fights NEW instead of ripping them out from boss fights you've already done. 
 
The weird thing is is that there seams to be no tails or Knuckles. Now provided if you like them or not, as a continuation from the original stories you would expect that at least they would be in them. Oh well at least they're in the right direction with this one. Watch the last boss at the end is some modified version of sonic 2 or sonic 3's Death Egg. 

My biggest beef with the game so far is the incredibly easy bosses. I constantly get ridiculous time bonuses at the end of the boss stages for beating every boss (except the instant-kill squish-you one) in like under a minute.

This game is ok just hope sonic colors is good. Last good 3d sonic game was heroes because the levels were more like the original genesis levels.

The trial was okay. I still want to see Sonic die a horrible death.

I'm really underwhelmed by it. Sega just keeps beating an already dead franchise into the ground.

Things I hate: 

1. The floaty animations of God Damn Sonic and the way they rely too much on the targeting system.
2. The shiny-ness of God Damn Sonic
3. The shitty walking animation of Gad Damn Sonic
4. The slow feeling of God Damn Sonic's movements
5. The fact that he wasn't officially renamed "God Damn Sonic"

1. It has the feel of a classic Sonic game. The atmosphere is right. That said though, it still feels forced or fake in some way.
2. The Environments are nice, and HD graphics really help that

Iphone version is the worst. So if you are really interested in the game pass up on it. The Wii version is fine though. There are annoying places that stop you outright and make you go through a jumping puzzle but the other stuff is fine.

This game is a good time. I enjoy it, and will continue to play it.

I don't agree that Sonic is dead and should be buried. They just need to get back to basics, and this is the most sincere effort to do so that I've seen in a long, long time. I'll buy it to support the sentiment.

I hate the physics but once I got used to it It was fun. Just not up to my expectation. And I should of known that the "Episode 1"  bs is just a way to sell you parts of a game. 

I thought the demo was fun but paying this much money for this amount of content seems crazy.  The demo took less than 2 minutes to beat...

The "Finish Zone 1, Act 1 in less than a minute" achievement is a bitch. Which kinda sucks, because I can get through Emerald Hill Zone, Act 1 in something like 0:30...

I haven't been one of the people bashing every little detail..  but I must say, I am rather shocked by just how bad this has turned out. 

The physics, momentum and animation are very off, it doesn't feel or play ANYTHING like the original games.  Ontop of that, the music is horrible and the level design really falls apart after the first stage..  Much like the Advance/Rush games, it loses any sense of platforming and resorts to boost pads and running in a straight line, and usually results in you falling off a bottomless pit to your death.  Horrible, horrible game and certainly not worth $15.

" I haven't been one of the people bashing every little detail..  but I must say, I am rather shocked by just how bad this has turned out.  The physics, momentum and animation are very off, it doesn't feel or play ANYTHING like the original games.  Ontop of that, the music is horrible and the level design really falls apart after the first stage..  Much like the Advance/Rush games, it loses any sense of platforming and resorts to boost pads and running in a straight line, and usually results in you falling off a bottomless pit to your death.  Horrible, horrible game and certainly not worth $15. "

Circle of Sonic all over again. 
 
Interest piqued as they claim they'll go back to their roots. But the lack of Tails and Knuckles (as far as I know) is going too far since this is "Sonic 4." 
 
Media coverage makes it look at least okay. The parallax background scrolling makes me smile. I see that Sonic has a homing attack, and then I frown. Faceplam each time they're showing footage of it and he's killing enemies with the push of a button. 
 
Then I hear that the game is a "re-imagining"/mixure of old levels and new ideas. All hopes are gone by this point, because now it's just a Sonic '2.5D' remake with the added homing attack making the game play itself even more automatic than a normal Sonic game. Start wondering why they haven't been able to find a decent level designer for however many years since Sonic 3 and Knuckles (while I did like Sonic CD, the level design wasn't the greatest). 
 
And then I stop caring again. I'm not like the crew of the Bombcast; I totally think a new Sonic game could be made today and still be good. I'm resigned to the fact that it will never happen, though, and I'm baffled how Sega keeps trying to nail it and does everything wrong in the process time and time again. They really should stop trying and have Sonic Team/whoever they're going to contract to help Sonic Team actually develop a new and interesting IP, if they can. 
 
Now that Duke Nukem Forever is coming out, Sonic is the biggest joke in the Video Game industry.

 Now that Duke Nukem Forever is coming out, Sonic is the biggest joke in the Video Game industry. "

i thought it was amazing. my expectations were so low, since i've hated sonic after sonic 2, but  this is a great game
me and my family played it and enjoyed every bit of it, i'll be picking it up tomm

To those who've played it, how does it fit in with the other Sonic games made by Dimps? Better? Worse? Somewhere in the middle?

This is pretty fun so far. Only a couple stages in, but it's cool. My five-year-old son is a big old-school Sonic fan and is going to love it. Sonic sometimes feels a little sluggish, not as light and quick to accelerate as the original games, but it's not all that bothersome. Each stage feels really large, especially vertically, so it looks like there's a good amount to explore. Looking forward to playing it some more this weekend. 

And I'm not ignoring your question, @FreakAche, I'm just not the best guy to answer it. 

I dont care for it whatsoever 

It's looking good. Haven't played it yet.

At first I didnt like it, the camera is zoomed in a little further than I thought it should be, and the movement seemed a little slow. It was much much harder to tell where exactly I was going in some situations. I am the kind of person that likes to find every little part of every level, so speeding through the thing once isnt always the most fun for me. After playing it for a bit though I have come to actually like it. I dont hate sonic like everyone else. I loved all the first few sonic games and then only really played Sonic R since then. So this game for me is just the next sonic game, not some attempt at reviving a almost dead, dirty, used up whore of a game. 
 
In conclusion, I wasnt sure at first, but I am actually really starting to like this game. I think everyone should really just block all the other sonic games out of their mind, because for someone who never played the shitty ones, sonic is still something pretty cool. I will say that all the characters except for sonic, tales, and doctor robotnik (eggman is the fucking dumbest name in the world and it whoever decided to change the name needs to punched in the face) are pretty fucking stupid.

I just played through the first act and started doing some speedruns of the early levels, managed to get the trophy for beating 1-1 in under a minute. The movement seemed very sluggish at first, but once I realized you can use the homing attack without a target to accelerate really fast things started feeling much better. 
 
Overall, I'm liking it. I've never really had much investment in the Sonic games, being a Nintendo-only kid back in the day and only sinking my teeth into the 2d Sonics on emulators years after they were relevant, so all the crazy overreactions to what Sonic is or should be have kind of gone over my head. I'll still take Mario any day of the week though.

Sonic is too damn slow. Otherwise the game is ok. Not better than the Sonic Advance games, but still good.

It's okay but isn't worth the price of admission.

I hate the way sonic jumps. It's horrible. The way if you jump to the right and then try to move him left a bit he doesn't keep momentum. ARGH. Where's the momentum. MOMENTUM. 
 

MOMENTUM 

Only played the trial but would it way too slow. Add to that the fact that if you stop holding a particular direction Sonic just stops. All it needed to be IMO was an vast expansion on the 2D sections of Sonic Unleashed. The 1 thing I did like was hearing the classic "SEGAAA" when you start it up.

Sonic is way floaty here. And that's really bothersome for me, because Sonic typically felt like he had some heft in his jumps. And the running/walking animation doesn't look quite right. Hard to explain, but it just seems like there's a disconnect between how far his legs move and how much ground you cover, no matter the speed. Almost like Sonic is animating too slowly for how quickly the world is moving past.  
 
Also. Dude, the music. That shit's fucking awful. Special emphasis on the "Extra Life" noise. Goddamnit. 

It's Sonice I guess but it's not what it used to be.

I don't mind it, but I'm not jumping up and down for the "next episode", whatever that may be. 
It's hard to find faults with it, because it's what I was expecting and wanted: A new old-school Sonic game. Nothing more, nothing less. 
 
Now that we have and Sonic 1-4, SK and even Sonic Adventure on XBLA...can we.....I dunno...maybe get that other Sonic game?
 
Ya'know.... The hands-down-without-a-doubt best one? Is that too hard to ask? :P

I kinda wish it looked more like this. 
  

 I've only played the trial game, but was completely put off. 
The graphics and the music seem off key, Sonic's handling is way to heavy and the level design was (And seems to continue into the game) haphazard. 
  
You can probably get Sonic's Ultimate Genesis Collection for less than they want for this episode and play through my personal fave Sonic 2. That game is still great, even though that motherfucking Death Egg still haunts me! 
 
And there are some good ideas here. I like the addition of the lock-on. I'm one of those who actually liked the Sonic/Shadow levels in Sonic Adventure 2 on the Dreamcast and it's pretty rewarding when you get in a combo-esque groove with it. Of course it's a total bummer when it all goes full stop cause you miss something, but I'd imagine the perils of fucking that up are easier to control in a 2D space than in a 3D space. It just seems that Sonic's momentum isn't right. 
 
Again, I'm just going off of the one act you get in the trial and this QL, but they seem SO CLOSE ye SO FAR from what I thought would be good. I mean, why the hell do they have this lazily cel shaded model of Sonic? Wouldn't he look super kick-ass if they did super detailed ultra hi-res sprites a la King Of Fighters XII. 
I think that'd look awesome.

It's good.

The new way he plays took some getting used to but after I did I started to like the game.

The shadow/light on Sonic's body looks like bad JPEG compression and everytime I look at, I see it.

It feels wrong, but lets start with the good. 
Graphics are great and looks super nice.  Love the water and just the clarity there is.  Especially the blue on sonic. 
The music is awesome, so in line with the genesis but of course better quality. 
Everything is there that should be and everything that shouldn't is gone.  Rings, super shoe, loops, speed boosters and jump springs. 
 
Now the bad.  As soon as I started moving, I was like, what the?  He starts off too slow.  And it takes a while to get up to speed.  Now, I remember the first sonic and it never took him that long to get up to speed.  Also, the camera seems too zoomed in for me.  Felt like you could see more in the first sonic games. 
 
The game is pretty good though once you get past some issues but it just feels like stuff that should have gotten right.  Its like they saw video of the first sonic being played, not like they played it themselves.