Reminded me of Destroy All Humans! While playing the first level I was thinking “would be great to get upgrades” and then I did after finishing it :D
I got a bit of framedrops when firing the laser in like level 5, maybe because they were too much people or aliens.
I suppose the game never ends until you lose? I found The difficulty was ramping up quite slowly and I just stopped after like level 7 or 8.
Simple graphics & music but they get the job done and weren’t annoying.
Good job overall!