3 Points

0 A.D. is a free, open-source game of ancient warfare.

3 Points is a map for it. 3 points has 3 islands, 3 players, and and a whole lot of water.

Reference

• 0 A.D. Modding Guide
• Guide for publishing mods on mod.io - Game Modification - Wildfire Games Community Forums

Links

• 0ad-matters/0ad-maps: Unofficial @0ad maps that focus on placing teammates more closely together