It needs a more satisfying audio-visual feedback when you kill an enemy. Also, I got the same issue with the final upgrade for the wall also "breaking" the screen by stretching it (was playing in browser, Firefox, in fullscreen). Additionally, at some point, the passive income druid button broke such that the displayed cost was 6100 but it would actually charge me 12200, so there's some sort of issue there. Last bit of feedback, there's too much of a span between the questions from the Robontu character and when I finally buy the space ship upgrade, meaning I answered them all WELL before I could beat the game. Maybe this is intentional so that you forget about them by the time it ends, making the reveal that they affect your ending more of a surprise, but this still felt like it was TOO long. Maybe there's a way to spread them out based upon how close you are to purchasing that final upgrade (like 60%, 75%, 90%, ya know? Just arbitrary examples here). Oh, and there's a weird behavior where the spaceships "twitch" above the scrap when they're trying to collect it, and then seem to miss collecting it for an arbitrary period. Might be based on the animation cycle of scrap making it so that it's not "touching" the scavenger bots and they keep trying to "collect" it by moving back and forth. Hopefully I'm not overexplaining it and making this description confusing!
All that said, if you iron out the bugs, and make the enemies dying more satisfying, even something as simple as them shaking before disappearing, just something to make me feel like I effected the enemy rather than just replaced it with the scrap unceremoniously, this could be a pretty fun game.