The game colors really reminds that you are on Mars, the spider took a while to get down and when I got stuck behind her, I just spammed R to be on top of her and kept shooting hahaha. It would be nice if the spider's health was always at the top level of the layer, because it was getting behind the arena sometimes. An option to change the mouse sensitivity would be good too. After victory or defeat, the cursor disappears, so I'm stuck in that screen. You could make shortcuts for the button (like pressing Enter would activate the button) or just make the cursor not disappear. Nice job!