Some genres lend themselves better to mobile platforms than others. Clearly, anything intensive can get problematic. Touchscreen only devices will certainly not force complex control schemes on their players. Apart from a generally changed life situation, this is one of the major factors in the rise of so-called casual games. Andor's Trail is a curious one on such an ecosystem.
Basically, it is a console style roleplaying game with Roguelike elements, such as randomized dungeons. As such, its scope is quite large; although it cannot even be finished yet, it can be played for weeks without having seen everything. Its core mechanic actually demands dedicated play sessions, but we'll come back to that later.