A pretty fun map by LosTacos. It was also on war3 back in the day.
As the title suggests, you build a maze/bound that has a start and a finish, and you can also place obstacles like siege tanks, colossus and patrollers with complex patterns.
You can play other people's mazes too, and they can play yours. You play them by spawning as a runner that can be either a marine, zealot or zergling, each with different stats and abilities.
Save/load seems to not work right atm, but I hope that gets fixed.
I highly recommend it

It's a little far down the list but it's not impossible to get a game going. I hope we can play it at map night!