Both BPM and Metal: Hellsinger come to mind as two good rhythm based shooters, with the latter being inspiration for this one alongside Hi-Fi Rush. I'm sorry to hear it wasn't running too well for you - some optimizations might have fallen flat at the last hurdle due to having to pivot from a web build to windows rather suddenly near the end of the jam.
As Mya said - the SMG is probably gonna become a burst weapon, as I think it'd fit the vibe like you said a lot better. The pistol might also get tweaked and rebalanced a bit, so that each weapon can fill it's own specific niche in the sandbox a bit better.
I'm glad you had fun! The soundtrack is fire, and both composers absolutely knocked it out of the park.