I would love some multi gameplay. Coop could be first . One person can choose one hero. Mission should have a lot requirements plus notifications like "Your friend have chosen red character you must pick between blue or green". Each turn could have min and max tick duration (min 5 max 15 for example plus maybe depending on class? More ticks for blue less for green?) and you always can end your turn after min ticks if your friend has better hero for next room . Even missions can be hard, why not? I like challenges if they proper rewarded.

Are you working on some multi staff anyway?