This was a lot of fun and I think it'll make a really good game. I love the simplicity of it. I wonder if it would be more fun to have some sort of upgrade system. Something where you can put points into attack, defense, health, and other bonuses.
That being said, who knows because the simplistically of this game makes it fun at the same time. Perhaps adding all of those features wouldn't make it more fun.
I would have never even come close to winning if it wasn't for the space button hint. I got to level 11 and then just couldn't get past it so I gave up. I ended up reading your response to some reviews about the slow motion button being a big help and it easily got me pass level 11 and 12.
I'll never be able to get the 10 minute medal, but I'm sure some of the more extreme gamers would be able to.