This is such a great concept, we did a very similar idea with hero kits and comedic theme, so I can really relate to just how much time and effort this game took to design and execute. Sadly, in a similar way, I found it really hard to understand what I needed to do, even though each hero's abilities were well thought out and very thematic/amusing. Perhaps there are too many characters.
One control change I would make is switching "switch character" from P to Tab, because as it is you need to take your hand off the movement controls or mouse to switch characters and as a player that makes it very awkward to play successfully.
But I love the concept - it's funny, silly, quite innovative and really hits the nail on the head with the theme!! With more time and attention, this could be a full release game. Cracking stuff. :)