This game looks so cool. When will be made compatible to the current macOS?

Still early access... is this game abandoned or still being developed?

What do the stat upgrades after each area actually do? I figured out some of them like heal, extra bullets, and more ricochets but some I just can't figure out. I was looking for a guide or something online but I couldn't find anything. Also the arrows in the corner seem to be some sort of currency, but the amount seems to go up and down randomly. I don't really understand that either....

how do you access it... just want to beat the game once

I appear to be stuck. No respawn button eh? (I will try to attach the image) (I cannot attach images)