Horse-Pike-Sword
Nothing is impossible!! Combining "rock-paper-scissors" formula, extremely tight space, and units with low bar (8 minutes), we get this battlefield where micromanagement and reaction speed are everything you need to be victorious. 100% challenge: When the 8 are fully playing, any missclick dooms your selected unit.
I wanted to load it and take a screenshot... but I couldn't... It's too scary to be honest.
EDIT: Final Version.