I like the style and play of the game, but I do have a few suggestions:
There seems to be too few health drops, leading to death by the "heretic" bats. This point is especially troubling when paired with the next issue.
The movement is a little clunky. A bit less start-up time for running would be nice, as it feels too slow to get moving once stopped.
For the upgrade menu, I have gotten the same upgrade for all three slots. Perhaps ensuring that no duplicates appear would be good.
The electric field is too small to be immediately useful, leading to a worse off position. I believe increasing its starting range would help it.
All in all, though, good work so far. Hopefully, some of the issues could be addressed without too much hassle on your end.