Most underrated title on the XBLA to date.
Marble Blast Ultra was basically a launch title for the 360 and one of the first XBLA titles that was poured over by the millions of users jumping on the 360 launch train, and those wondering about the system alike.
Today, I hear people tell others to avoid this title and to buy Geometry Wars instead. To buy Uno instead. To buy some other game instead. Yet every time I hear this, I wonder why it's being said.
Marble Blast Ultra is a little easier to imagine if I put it this way: you're a marble. You roll around with realistic properties in a world with realistic physics. Your purpose in this game is to achieve the goal of reaching the end portal of a level, which is just a column of light shooting out of the ground. But some levels require you do to gather up red crystals laying around the level in order to make the column of light appear.
Now it sounds simple and fun and boring and dumb and ohh "look at me, im a marble, i roll this is dumb".
NO. YOU'RE INTENSELY WRONG.
Some of these puzzles will destroy you, others will amaze you, but most of all, they'll all be extremely fun. You'll be doing loop-de-loops, shooting off from inexplicably floating platform to inexplicably floating platform at extreme speeds, you'll be gathering power-ups that change your size and give you rocket boosts in whichever direction you're moving, all just to finish the simple goal of passing through the obstacles to get to the end of the level.
Which when you're given power-ups, realistic physics, online-play (it's a lot more fun rolling around as marbles with friends when you're shooting around with rocket power ups at 900 mph than it sounds.) and tons of interesting puzzles, the only disappointing part of the game is how few people have played it.
If you like puzzles, and you like meta-gaming for that perfect level time, then there's no reason you shouldn't own this game other than not owning a 360.
Which there's also no reason for.