Haven't played online yet but offline is ok.
Sadly suffers from 360 controller syndrome like every other game out there, but you can get by, just.
Seems to play mostly like the original arcade game, so drops are not as forgiving as the later games - i.e. you'll get crushed when you might think you would otherwise slide out of the way. Along the way you pick up treasure chests containing items - these are the items typically found in the quest modes, like add 5% to max air, fill your air up, barrier, fast digging, etc. but you can only carry one at a time and it gets overwritten when you find a new chest. Thanks to the items, it's not going to be totally impossible to get the high depths. I just got 2400m, which I would struggle with in the regular mode before.
Quest mode is also semi-interesting, though usually the stress of the quest tends to distract you from playing properly, so it's a bit harder than regular mode.
Wish they'd left in the Japanese samples for picking up air and when the game is over. It doesn't sound right without them, but I guess the localised versions never had them?
951050 is my high score so far... 39th on the table :/