Thanks for feedback.
Regarding difficulty and resource management: Try spawning more enemies. But it is a demo after all, not really supposed to be difficult. The main loop will not be a survival / wave based thing like this, this is just demonstrating the movement and some systems.
I wanted to make it feel like you were controlling a ship/submarine in water, and I feel like if there were less drag and stuff, controls it wouldn't feel like that anymore. But I hear you about the weapon pickup stuff
Yeah, this is gonna be a PvP game at the end of the day, so I figure full vertical movement would break a lot of things. I wanted to emulate the feeling of a jetpack or something like that
I hear you about the primary weapons. I'll buff them up.