Excellent little survival game you've got here! The only issue I had was with learning how to play the game - my Xbox controller didn't seem to work for it, so I was just pressing buttons on my keyboard for the first few attempts until I figured out the interaction buttons. That being said, it has a very nice gameloop of managing your O2/energy, hopping into the mechsuit to defend the base, and breaking rocks as fuel to escape.
My favorite part was, of course, the mech. The little map indicator made it very clear where I was aiming and what asteroids I had to prioritize shooting first to protect the dome. The graphics in general (but particularly in the mech) are great, and the music is very nice! The tilting of the pixel graphics on the asteroids makes it a bit less gameboy-ish in my opinion (diagonal pixels), but I do love the motion of the asteroids in their animation and the tilted asteroids do fit the graphical style of the game very well.
Overall, though, great work!