There's honestly a fair amount of games you can play on mobile. As a mobile player myself, Joiplay has been invaluable. Most ren'py and RPG maker games can be played using it, though you'll occasionally run into games that don't work for whatever reason (I'm looking at you, My Futa Family, no android port having ass), but the majority will be playable.
Joiplay will also let you play HTML games as well, though most are ass, and the good ones (like Degree's of Lewdity) will have an android port already.