What’s the core experience of the game?
Understanding what the central player experience is the key to ensuring the game design aligns with your vision. Furthermore, it also helps ensure that any updates or changes you make to the game don’t disrupt the core experience that attracted the players to it in the first place. I’d design a role prototype that would focus on the most central mechanic of the game like a paper model or basic storyboard. My prediction is that the mechanic that produces the best social interaction will succeed.
What is unique about the game?
Knowing what the unique offering of your game is or how it is different from others will help make sure that there is a core “thing” players love and can’t get anywhere else. To test this, I’d design many iterations of the game around the core mechanic or unique offering, comparing the playing experience to other games in the same aesthetic. My prediction is that the prototype with the most unique offering will succeed.
What’s the learning curve for playing the game?
A lot of games are extremely fun, but may require steep learning curves as a result of their complicated rules and mechanics. This often deters new players to the game and can severely hamper the playing experience. I would design a prototype that is solely focused on the core rules and mechanics of the game to isolate this learning curve. My prediction is that the prototype will be successful as the learning curve isn’t too steep.