"Mob" Themed Puzzle Map [PROJECT ABANDONED]

I've just begun my first puzzle map, and I was wanting some feedback.

The idea is to create several progressive stages, each themed with a mob from the game.
The first is not themed, I am just a fan of mazes and I wanted to create my own.
The second stage will be a 'Zombie' stage, where it will be a gaunlet run, with pison bumping you off the stage.
The third, will be a "Skeleton" stage, some kind of arrow firing range or something similar, possibly join it to the zombie stage and make it a gauntet also.
The fourth will be a "spider" stage, a jumping/parkour challenge. I want to make this a little different though, I need to brainstorm possibilities with this one.
And the final will be a 'Creeper' stage, a lever challenge. In my mind it will be like russian roulette, except instead of one bullet it is one lever to move on or something.

So far I have completed the maze stage, but like I said I would like feedback so I can fix and update it as I go.

*Update 14/12/2011* - I've completed another two stages, the Zombie and Spider stages. They still need polishing up just small things like items in chests, and what blocks to use for decoration. Still need to work on the Skeleton stage, I just hate dispensers, and the Creeper stage (just a little bit more redstone wiring to be done. I've added a lot more bonus things in, including one that is very hard to reach, but is very rewarding. A little advice with the Zombie stage, it is all about timing and what piston is active. It does work, I have completed it, don't blame a glitch you just need to fiddle with it. Also because I haven't really given you many items yet I would use too many items or similar just to help out.

*Update 21/3/2012* - I've completely abandoned this project, I've honestly just gotten bored with it. Sorry for anyone who was actually interested in it.

Thank you
Lee Geeves