I actually have an idea for stuff like this as an adjunct to a MMORPG game where somewhat less exciting activities (managing 'growing' resources over time) is to be done on handlheld/tablet interface devices 'offline' from the main game (PC or platform with full FPS graphics) .
Efforts done while the player is stuck in daily situations feed into resources available in the 'online' game (and its optional but efforts expended have positive results in-game).
Whole varieties of different activities and mini-games would be the idea (many people have limited at-home playtime and this stretches that time by moving the tedious stuff offline). 2D and 3D (they are getting better) interfaces for more 'retro' styles , not effected so much by handheld devices limitation
Better would be a MMORPG where players can create mods/scenarios for such games (tap into players creativity and also alleviate the stagnation of not enough new material for longtime MMORPG players)