Very fun, but I don't feel a "space" vibe or I didn't get something maybe. 

Notes from gameplay:

- Graphics are simple, but work fairly well to convey what they are. Chests are clearly chests. 

- Enemy art and explosion animation is well done, reminds me of old atari games like Turrican

- Music is a bop, but could be a bit more spacey to fit the game vibe. Loops well. Replaying the game via space does not END the prior playing track, so tracks double up.

- Left click on rock while holding pickaxe doesn't seem to mine

- Shooting feels smooth, intuitive and easy. Aim handles nicely and enemy wave movement speed is a nice challenge without being too hard.

Decent little prototype to test out some different mechanics. Nice use of sound and art assets to create a cohesive experience.

I'm sorry I didn't get it. You might want to add a manual or something? 

The concept of the game is really cool. Nice idea!