Bloxxerbot: Why would you need infinite shots when there are a finite number of chances to use them? It adds more variety (and you could argue skill) to the game when you have to use different weapons. That's the reason they are there in the first place.
Health regeneration is so slooooooooooooow. Which becomes more of an issue at higher levels when you don't have the inventory space to carry healing items since you have so little space. There are so many small annoying problems with this game that I dislike it, damned badges!
It would be nice if you could actually start the game rather than having to wait a deecade to get through the 'tutorial'. Seriously, it's not exactly complicated to say "Aim with the mouse, move further away to increase the power of your shot, only shoot at the same coloured blocks. Now play" Yet you have to wait until after the next ice age before you get to do anything.
I take it you have to pay for enemies to die properly, I just had a knight stuck under half of the castle and he was just happily squashed there without dieing.