I like the concept, nice little vampire survivors-like. I also like how the upgrades get added onto the beetle's back kind of like risk of rain, that's definitely something I love seeing in these kinds of games cause then you character just ends up looking pretty insane by the time you have your 30th upgrade.
I found it hard avoiding taking damages because I was so large and there were so many tiny enemies, and the play field was also quite small. Also my guns would both target the same enemy who would die in one shot anyways, so it could be nice to have both guns focus on different enemies so that I'm not wasting shots on one-shot enemies. I also wished there were some sounds, but I get it might've been more important to focus on the core game play before extra stuff like that.
The upgrade system is pretty nice tho, very typical leveling-up upgrades but it works well and has some good diversity in upgrades. I find it interesting how you can have your upgrades in a separate inventory and change your whole build on the fly, and I'm sure that could lead to some interesting game play. Again though, I never made it too far because I would get swarmed, but maybe that's just my fault.
You got some good ideas here, and I enjoyed my time with your game! Keep up the good work!