I'm guessing you mean the maps after the first five in the "Normal" set? Have you tried any of the maps from the other sets? they have different progress so the first map of each set is unlocked by default. I'll look into re-balancing map 6 and up from the Normal set first.
I meant I'm overly familiar with my own game. Its hard to balance things when you know exactly how everything works. The Worms games were of course an inspiration but this isn't meant to be a clone or anything.
I'm experimenting with changing the projectile collisions including head-shots. Different game modes are a good idea, I’ll look into making some puzzle maps.
The default Custom map is just an example for making custom maps. It has all of the weapons available and the spawn rate isn't paced very well. The regular maps that have weapons (mostly the "Ghouls" set) have a much lower spawn rate so hopefully isn't as confusing. I will look into adding something like an inventory though to make it better when there are multiple pickups available.