Eww, needs to be final compiled.
Misaligned textures:
The boxes which you use to jump to the tunnel in the purple side
Most of the walls
The barrels in the tunnels
Most of the metal textures (at the lift thingy, next to the flag..)
Some things I would fix:
The lamps in the tunnel, I would apply a metal texture to the bottom of it.
I would scale up the fence textures, they look really tiny.
The ice doesn't look like ice, maybe change the texture or make it transparent?
The "lift way" is way too long and slow, no one would use it when they can use the simple, fast tunnel.
I might have forgotten something and was too lazy to take screenshots but who cares.
It looks pretty good for your first map thought. Just light it and spend time with it, it will eventually become good