This build, obviously, was meant for killing zombies in an arena type style.
rating is allowed but no flaming please, i also know that it is rather spammy and i will eventually fix that, but not right now. Also it is meant for function, NOT looks. the reason it is so large is because i like to use the portal gun to kill the zombies, so it needed to be rather tall.
overview of the front

start spot along with teleport to the top

observation area (the roof basically)

what one might see from the observation deck

selection area, click on the red button and a bullet will be fired at the panel of numbers, determining which arena you go to. (cred to space guy for giving me the idea)

this is level 9, the hardest level. All that is in it is a zombie tank but the rest of the levels are simpler and easier. the white thing in front of him is the "starting system", which basically is a turret that fires a gun at him to kill him

me, this is mainly for L, who wanted to see a picture of me in-game.

Another view from the top

View From NEW inside

it doesnt really show it, but at the observatory there is a start button, along with a teleport to the selection area. just like the last one you really shouldnt have to use your jets in this build. when you die you respawn at the bottom next to the teleport to the observatory.