Very impressive! Unfortunately I do not see the cursor, so shooting is hard and I have not been able to do any merges :-( Could that be a bug? Playing under windows.
Still, got to a high score of 385 :-)
Viewing post in Project M.E.R.G.E. jam comments
This really seems to be a bug we never had. If this even happens if you restart. I would say you should try to clean up the game and unpack it freshly. There are some user files under: \AppData\Roaming\Godot\app_userdata\Project Merge, just delete the "Project Merge" folder.
Otherwise it is possible to play without merging, but it will be super hard as you probably got to experience already.