I like the concept of it! Having multiple characters with abilities is always intriguing xD
As others mentioned there are some out of bound bugs (which apparently didnt get fully fixed?). It happened mostly with Fauna by shooting them out of bounds for me. It also took me a bit to see what in the UI is for what (like HP bar/time, ult bar etc.). i think simply labeling them might help out a lot or having the information also shown as numbers (like for example % ult charge or time left in an actual countdown format)
Also a little music also does a lot within the stages! i liked the menu music though!
Great Job for all the mechanics involved though!