The torment quiver keeps becoming blacked out and unusable even though I have plenty of souls. The only fix there seems to be is to unequip and re-equip it each time. I believe it may be caused by having other multi soul using items equiped?
The torment quiver can also be a massive exploit going through walls. The secret boss can be cheesed by hiding behing the large rock in the lower left corner and shooting through the rock.

A lot more clarity is needed on item enchantments or the ability to unenchant items without scrapping them. It is not clear how enchantments will work together in reality and I have often been disappointed if growing, multishoot, chain reaction, fuse shot and poison cloud for instance don't work together. The most obvious thing would be to allow players to unenchant them, at least for an hour after choosing.
Lots of instances of enemies dropping through the floor and being under the map. On the final map enemies swarm to the edge of platforms even though they can't get to you and if you shoot them they often fall off taking any items with them. Not sure if that was intended.