Eaters in a (not so) peaceful sky

Eaters in a (not so) peaceful sky is an arcade survival couch game which can be seen like a "Lovers in a dangerous spacetime" except you are some trapped scientists inside a demonic ship surviving by shooting gastric acid outside on nazis. It has been created as "school project" but we want to go further with this game. We have plenty of ideas and features to add (and we had to cut a lot to make it in 6 weeks so we also have unused assets and mechanics). This is supposed to be a 3player game but...