This is the most detailed review I've gotten yet, thank you for that!
Yeah you're right, graphics are the main thing I need to work on in my games. Luckily I was able to work it into the arcade theme this time so it turned out alright.
Powerups are the main gameplay mechanic that I'd like to put in a future update after the jam. Making them appear at certain combos is a great idea that I hadn't thought of but now I probably will do that if I get the time :D
Yeah the spikes do sometimes spawn a bit unfairly. I think I might increase the minimum distance away from the player that enemies have to spawn instead. I didn't want to add an enemy spawn indicator because I felt like the spikes could become too easy to dodge, but I can always implement it and see how it changes the game.
Thanks again for playing my game and leaving a helpful review :)