The floaty controls I can understand. It takes getting used to. Lives don't matter when dying makes you start the whole level again, and Meat Boy doesn't have check points. That's kind of the point. You play the level until you've mastered it and get an A+ or pass it period.
Like this.
I'm not sure how lives/checkpoints factor into it when you're required to start the level over every time you die. Lives in platformers are also a waste of time and redundant. In Mario games, when you run out lives, you start at the beginning of the stage again, anyways. Which doesn't really mean anything because you're going to do it again anyways. Super Meat Boy isn't that type of game. Its difficulty is consistent. More than that, the stages that DO have checkpoints have iives: warp stages.