Absolutely bursting with creativity, and every level is uniquely memorable. It's got such a chill feeling to it, thanks to the charming graphics and generally laid-back soundtrack. Its casualness makes it the perfect game to play with a friend or family member who doesn't usually play video games (I have great memories playing it with my sister when I was young). And unlike most other games that try something similar, the transformations are actually a good deal of fun and a welcome shake-up to the gameplay (though as with any game, some are better than others). I remember the fact that you're unable to die at all within the game ruffled a few feathers upon launch, though I find it hard to picture any other way. It's just not made with a health bar in mind; you're unlikely to get hit enough for one to matter anyway, unless you're not very good at the game, in which case you'd probably rather not have one. The only way I think a health bar would work would be if there was an entirely separate difficulty mode for it, which also reworked enemies and stages to make them more difficult. That'd be a super cool addition and I think would add a lot to the game for fellow challenge seekers, but I can get that that wasn't the kind of thing the developers were going for. The game does get slightly harder as you go along, but with no way to die, it feels a little weird. Later levels like those in Space Land and Dream Land definitely have tougher obstacles (Cloud Palace is almost entirely bottomless pits!), and it's much harder to get through without getting hit, but simply beating the level is something you can still just power through. The medals and streak system give a general measure of how well you did in the level, though gold medals aren't hard enough to earn to feel like much of an accomplishment, and there's absolutely no incentive to get a high streak, making it easy to completely ignore so long as you're not a high score chaser. And the little challenges that tenants in Quilty Court give you are a nice addition to add a bit more meat to the game, but nothing too crazy. Despite how polished each level is, it generally feels hard to play the game for very long at once.
My thoughts here might not be the most organized, but what I mean to say is that I can definitely understand the game's reputation as “baby's first video game”, but dang is that baby getting a good introduction to the medium.