Even after reading the new controls you posted (thx btw) it took me a few seconds to understand how the gun worked because it's a really off the wall mechanic. But when I figured out what was going on in this game I got excited about it. Having to stop to pump up the gun leads to lots of interesting decisions when the pressure has mounted. The question is not only when to stop and charge, it's also about how do you "spend" the charge wisely enough to create another chance to charge. The charging also created an interesting feeling of power, like I was really putting a bunch of energy into the gun and then blasting it off. I think this is worth expanding on and if you do I have some suggestions. Spamming R so much is hard even for me with no disabilities or medical conditions. If you change it to holding R I think the essence of the game would be the same but make it a lot easier to just play. I also think it would be cool if there were different guns that had different gimmicks for reloading them. 

good 

This is pretty satisfying to play, cool little game!

Controls:

WASD to Move

Left Click to shoot

Left Shift to enter/exit charging mode, spam R to charge

Esc to pause

F4 for fullscreen