This is great fun, the set firing angle is a clever twist that adds a lot of tactical play to the formula. I'd love to see this fleshed out with more work on the balancing, the exp disappearing after a while makes sense when you reach the late game but it make it very difficult to gain momentum in the early game, especially with the speed being as close as it is to the enemy speed. It would be good to add some kind of scaling so that enemy speed and exp time start lower and built to the current level as the run progresses. It would also be nice to have a bit more feedback when getting hit. Overall though this is fantastic, well done!