That's a good realisation of "only one" and Morse! I liked that nice atmosphere and sound design. I thought that we would have some rare obstacles to evade, so player needed to move more often, not only for coins or good shooting position. Also, at the max level upper gun had minimum delay, when lower gun didn't change its shooting speed. Is it a bug or do we upgrade only the upper gun?
I want to see a full version of that game, that has a lot of Potench.