Very fun game with a wonderful aesthetic. It reminds me of many beloved roguelite games. The cats are adorable and the sound effects were excellent, although the multishot attack seems to be missing a sound. Some background music would have been a nice addition. I tried all of the weapons and the shotgun/sniper felt nicely varied, although the multishot felt like a weaker shotgun to me.
Importantly, I would highly suggest either reworking the player's movement (it seems like you're setting the transform position?) and/or limiting how many speed upgrades the player can buy. After buying about 12 movement upgrades, the player can move through locked doors, and 22 upgrades lets the player move through walls freely (to say nothing of how difficult the game is to control). I ended up skipping the last third of level 2 because I found the apple while speeding around outside the map.
Overall, I very much enjoyed this game, and it gave me the same fun as other games that I love.