I tried the demo, runs smooth !
Only probel there is no enought ammo , and when player pass over ammo icon , nothing happens, ammo is not recharged.
You should let your game be fun and not worry player about how many ammo it remains : perhaps lot lot more ammo, and some ammo packs in the level that would recharge alos a LOT !
Another suggestion , even for a demo :
a BIG Panel with a button : "REPLAY LEVEL"
This is borring 3DGS Games demos where you dy and have to quit the game to restart
!
Arrow keys to play , why not ?
Moer varied ennemies, and some shooting less, caus actually they shoot fast and a lot like the player.
Make them less powerfull !
Or they could shoot as fast , but only some seconds before recharging ! Perhaps keep that for the bosses.
The game is great , keep it up !
It is on IndieDB site ?