Not a bad concept, but...
This needs to be revised a little bit. I'm always one to be positive and praise, and I can say I like what you have going here. For one, even for a mini-game it gets dull after you game over; it's just not something I'd play again and again and again.
I think some endurance tests would be a good addition. Aside from that, I just think the visuals get stale after awhile. I think more art would be nice to throw in. Plus, the game gets somewhat redundant.
On the bright side, like I said, the concept is awesome, and I'd love to see an update to this. Nothing personal, the game isn't terrible, it just needs work, that's all. :) Keep it up.