Thanks for the feedback! I'm not really the best at making music and the loop is definitely way too short, but I hope it didn't severely impact your experience. Part of the low frame rates and lagginess can be blamed on Pico-8's limitations, but I do really need to work on optimization as well. I also think I should adjust the difficulty curve so it steepens a bit after reaching 8 upgrades, the main reason I kept it relatively easy is to not overwhelm people who might be new to the genre, so if it gets harder later it doesn't greatly impact their experience, but still provides a challenge to people who might find it too easy. Thanks again for all this great feedback, and I'm happy you enjoyed!