Wow, pretty solid arcade fun to be had here! All in all I feel like this is well put together and delivers quite well on all aspects: the combat is fun and fast-paced with great enemy variety that has unique AIs and attack telegraphs, there are a good amount of fun powerups and arena obstacles and great bosses to make runs feel different, graphics and animations are very juicy and the feedback from shots and blowing up enemies with huge chain reactions from items were so satisfying, and so on and so forth. Had a good time playing this a few times, getting good enough to loop over and over!
That being said, while I did have a good time, there are plenty of nitpicks I could make. For one, I was disappointed that the game doesn't have any sort of goal or story to it and instead starts looping as early as arena 4: as much as I did like how the enemy variety and such did keep improving on successive loops, it just started to feel repetitive and pointless, especially with how easy some of it could get without even needing items to cheese it. Also bummed out that there didn't seem to be any primary weapon upgrades, just subweapons, and that I would have to ditch old subweapons just to try new ones. Speaking of all that, I found it a bit confusing that I couldn't see what items I had already purchased and was unsure what would happen if I purchase duplicates: would they stack or just get ignored? There was also some confusion with visuals as, while most player bullets are yellow and enemy bullets are red, there were weird instances like items that would spawn 'friendly red' bullets that I thought I had to avoid in all the chaos.
Oh, and while this game does call itself a 'roguelite', I think that's a misnomer since that typically implies that some sort of progress or upgrade is carried over with each attempt, whereas this game just has you start from scratch each time. But whatever, it's all rogue this, rogue that, I think people just use those terms interchangeably nowadays, so I'm being needlessly pedantic.
Overall though, those nitpicks were small potatoes and again, I had a great time with this. Only reason I'm being so nitpicky was because I liked this so much and hope that you make even better games in the future!