Thanks for the feedback! I was able to beat the game, so it's doable, but the difficulty curve is a mess, It gets brutal near the middle and if you get through that, then it's a breeze. I spent a solid 2 hours trying to smooth the difficulty, but I just run out of time.
You get a big powerspike with the second fire power upgrade, as you become able to oneshoot the basic enemy, so get that asap