great third person looter-shooter, lacks end-game depth
Warframe is a truly great free-to-play (or at least free-to-try) third person looter-shooter. If you enjoyed Diablo, and you like third person and fast action, you should give this game a try.
Smash TV meets Tomb Raider, in Space
At it's core, is a PVE action combat game, that puts focus on fast paced arcade-like movement mechanics amidst lots of shooting and spell-casting.
Curiously, the early game experience does not do an amazing job of introducing new players to the many jumping, vaulting, mid-air-spinning, wall-running, and other movement mechanics that makes the gameplay so addictive. It's improved over the years, but it's still possible to try and play Warframe like it's a slow-paced military shooter, and just not experience the fun. New players are advised to watch a youtube video about basic early game movement mechanics, to really understand how to enjoy fast paced Warframe.
When it's at it's best, you are jumping and vaulting and flipping around a battlefield in superhuman ways, while simultaneously dispatching enemies, staying alive, and helping teammates. It's quite addictive.
There are also some really great story elements and reveals..
Part Game, Part Collectables
Unlike class-based games, in Warframe you collect equipment in the form of guns and "warframes". The structure of "collecting everything" is refreshing, and avoids the way class based games encourage straight-up replays of the game (with different classes) to extend enjoyment time. In warframe, you only progress through the story once, and your account builds and builds as you do, collecting more and more equipment as you progress.
There is also a bit too much confusing early revenue pressure in the game, in that things you really don't need to spend real-world currency on are shoved in your face as a money-trap, making it confusing to figure out what is reasonable and what is not reasonable to spend real money on. However, savvy players can keep their spend at reasonable $$ per playtime hour levels, as most of the items you truly want are earn-able with minutes or hours of super-fun in-game grinding.
Unfortunately, if you want to keep everything you collect, you'll need to spend real money to buy "slots", and a standard play-through collecting everything probably requires at least $100 in slot purchasing. Of course, you don't have to purchase slots, as you can sell items you no longer need. If you follow this strategy the slot-spend is much more reasonable, but you need to do more thinking and management of what to keep and what to sell. I don't fault them for this part of their revenue model, but I prefer free-to-play revenue models built more around early game boost-acceleration and vanity items, such as League of Legends, DOTA, or Fortnite.
Some even jokingly call the game "fashion frame", because one end-game activity is collecting all the fashion items in the game. However, given that many of them are only available for real money, this does not feel like a gameplay "end game" to me. Give me gameplay to keep the game going forever, and I'll keep buying vanity items because I want to look cool (And support the developer). This formula has made me happily spend more on League of Legends than any other game, despite nearly all of it being for pure vanity. Warframe, however, feels more like World of Tanks, where they provide an addicting gameplay loop, and then keep throwing things that cost money in front of you, hoping you'll impulsively bite -- even when some of these things can be earned with less than half-and-hour of gameplay if you know where to go.
Good, Bad, and sometimes Ugly Peer to Peer
While Warframe has MMO like elements, or at least Action-MMO like elements. The game uses Peer-to-Peer instances that have enough clunky networking issues that the game never feels like an MMO. It's more like a 1990s era LAN game, that didn't get the memo to stop using client-side hosts. If your host is lagged, the instance might be unplayable for you. If your host leaves, you might lose rewards during the host migration. However, if thought of more as a single player game with some P2P ad-hoc grouping, the system works and is pretty enjoyable most of the time.
What would make it better?
When I started playing the game, I would have said they should make service-side hosts. However, I eventually made peace with this deficiency and learned to just quickly quit an instance when P2P gives me a bad host.
Warframe's main deficiency is that the lack of end-game depth means the fun ends sooner than one would like. I enjoyed it for about 350 hours, which is an excellent run among games overall, but I admit that going into the game I expected it to eventually deliver a more challenging, deeper end-game that would keep me entertained longer. However, in the end, the super easy gameplay just kept on rolling, and eventually became boring to me.
In the end, what would have kept me playing the game is an escalation of gameplay difficulty, and end-game goals that I would care about -- one of which could simply be achievements completing truly difficult solo gameplay elements. Unfortunately, the game follows the opposite path, where you keep getting better and better gear, making the content easier and easier to complete.. and the content really just doesn't scale up to compensate.
Still, there is plenty to enjoy there.. and successive content patches keep adding more and more to the game. So perhaps, with time, they'll eventually add some challenging endgame for the still growing player-base.