I've updated 241, its now the oldest co-op puzzle map that still works in 1.12, just in time for the Better Together Update. now you can play it with all your friends.
Download «QuarCo-op» (19 mb) map for Minecraft
1.12] Two-Player Co-Op Map: The Twist Labs [Puzzle] [Adventure] - Maps - Mapping and Modding: Java Edition - Minecraft Forum - Minecraft Forum
RnB Co-op Map 1.16.4 for Minecraft - 9Minecraft.Net
Need help with my puzzle map (4 player co-op) - WIP Maps - Maps - Mapping and Modding: Java Edition - Minecraft Forum - Minecraft Forum
5 best Minecraft co-op maps for 2 players
Under Olympus - A Puzzle-Adventure Map by The Tater Team (1.18) Minecraft Map
Two For One Map 1.12.2, 1.11.2 for Minecraft - 9Minecraft.Net
The best Minecraft puzzle maps (mid-2020) - Gamepur
Maniac's Lair - Coop Puzzle Map For Minecraft 1.19 | PC Java Mods
1.12] Two-Player Co-Op Map: The Twist Labs [Puzzle] [Adventure] - Maps - Mapping and Modding: Java Edition - Minecraft Forum - Minecraft Forum
1.16.2] 2-Player Coop Puzzle: The Twist Labs (Remastered) [EN+DE] [Available on Minecraft Realms!] - Maps - Mapping and Modding: Java Edition - Minecraft Forum - Minecraft Forum