I like the idea behind your game but I think it needed a bit more to be really enjoyable. The graphics are nice but it's really hard to read the screen. Some actions are unclear, like vacuuming souls: I never know when the soul is fully harvested because there is no counter in the UI and the VFX of the vacuum hide the soul behind it. The power up selection screen is also unclear, and the car to start a new wave could be a good idea but it's too. damn. slow.
Sorry for this comment full of negative feedbacks but I really think your game could be better with just a few adjustments.