Good concept.
If you are experienced in using a keyboard this is quite easy and I didn't notice any changes in difficulty, this is why I stopped at 1300 on purpose... besides that.
Gr8 game!!
This is original and has good graphics and sound(when i say good graphics i mean the it has a high amount of pixels, not the complexity)
If you could change it so the difficulty increases a little faster this would be pretty fun.