Map name: Monolith
Theme: Rubicon
Playtime: 5-6 minutes
Target Difficulty: Hard
Author name: Salivan Bufrat

The map can be completed on any difficulty level. I haven't tested multiplayer, but it should work as intended. Deathmatch works, but I don't know how well it will play.
A little background: I originally wanted to make it so that after pressing the red button, a countdown would start, and if the player didn't make it to the exit gate and remained outside, the base would explode and kill the player. But I didn't know how to do that in vanilla, so I had to create a back exit from the level. I hope it won't be hard to find.