Lately I've been struggling with the question of how do I make a game that people will want to keep playing for longer, past the first impression, past the first level clear... 10 levels of this game later, I'm thinking I ought to stop worrying about that so much. If this were mouse+keyboard rather than just keyboard, I'd no doubt have immediately hit restart. Great entry, particularly love the cloud layer as a little touch that goes a long way!
If you were inclined, I'm sure you could develop this into a game one could sink an hour or two into.