My argument is through a multiplayer system, groups will be able to engage and create a dialogue towards the lesson content more effectively than when by themselves.
With gamification being pretty much solo events, there is little reason for students to talk between themselves.
The testing concept will be set up as a series of testing game types which each participant will playthrough the game as a single player.
The next step is for the students to team up and play together. Same basic test, but with different tweaks to keep the challenge present.
The data collected will be the time it takes, sure, but also how the team has to communicate within the party to share the final answer. PUt the pieces together, and the next puzzle is unlocked.
Testing can continue into other subject matters, and into varied degrees of difficulty.
Testing for the builders will be based on ease of use to build and establish the content effectively.