I didn't have any problems with responsiveness, but agree about the transition screens. There is a gate at 547m and door at 1522m that you must blast through with power, but if you use a boost just after hitting these, you can get through them anyway. The record for the game stands at 51,708, so I don't think it has a drago(o)n ending:(
A fun little game, I've finally beaten it, end screen was a let down. I see what people are saying about the sky/space parts. However, Kenny changes direction based on where you click on him, so it's not that hard. Invest everything in the save Kenny upgrade and you should manage after a few goes. Also the clouds help, since they slow him down and make it easier to click him in the right place. Good luck:)