Thanks for the thoughtful feedback! We fixed the collision maps for the spikes and are now evaluating ways to balance the difficulty. Check points seem to be the most requested feature so far. In regard to a score, we intially wanted to add a height score but ran out of time. Although we are now considering a score influenced not only by height but by defeating enemies as well.
We are currently working on the game and we'll address many of this issues in the next update. Thanks again for playing our game!