Thanks all for the great feedback so far!
@halfmule Yep, the music kicks in every time you defeat one of the big ghosts. I thought it might get annoying otherwise. The downside is that a lot of people seemed to think it starts and stops randomly. With hindsight I should have made it more obvious.
@geraldfingburke The eyes on your bat show how many lives you have left but I should have made this a lot clearer.
@barrier @aguahervida Yes, I realised too late that the enemy projectiles are the exact same colour as the goo. D'oh!
@nisco Solid advice about giving the player a reason not to shoot. If I worked on this more, my first move would be to either give some kind of 'ammo' counter or have certain enemies that you need to avoid shooting, I think.
@allenial Sorry about that, I never intended for players to have to read that more than once. I'll check but it should be set up so that losing a round takes you to a different, much shorter chat before throwing you back in.