Thanks!
I agree with you about Lil' Jim, I think some people will love him and others will find him creepier than the zombies. Unfortunately, despite being his inventor, I am in the latter group. Fun fact: Lil' Jim was originally going to be a small red demon.
The health indicator is the ice cubes in the lemonade glass, when the ice has completely melted your health is gone. The lemonade is your XP bar, you level up every time you drink all of the lemonade. This was originally going to be explained through dialogue with the Grim Reaper (he was going to show up every time you leveled up so you could choose your upgrade) but unfortunately we ran out of time before we could add it. I'll add it to the game description.