I'm normally not a fan of space invaders (nor am I very good at it) but I had a lot of fun with this! I managed to make it to the end, I was impressed that it kept going for so long! The powerups could use some balancing (I thought the bomb was lame at first but after a few upgrades it was the only reason I was staying alive lol) but the main game loop is great. It felt a little like cheating to mostly be making a hole in one side of the enemy formations to let them pass by me cause I couldn't kill them all, so maybe a small penalty for letting enemies pass by could be interesting? I could also see a meta-progression aspect where you can upgrade your overall health and stuff between rounds once you die.
Nice work!