Roller Coaster Tycoon classic is good on mobile, even with the small screen, I don’t find it fiddly to play at all really. It’s something I always come back to every now and then.
Kairisoft games are really fun and addictive! My favourites are game dev story, venture towns, 8-bit farm and pocket academy. Much prefer their paid games rather than their free2play ones.
Bitlife is great fun, I’m a bitizen! It can require some imagination as it’s basically a text based game. Sounds weird but sometimes I play it at night when I can’t sleep and it helps distract me and drift off. It’s kind of like reading but interactive.
Played mario kart mobile for a good while but haven’t in ages. I was getting decent at it as well. Good game but I always get a bit bored of free2play games after a while.
Animal Crossing - same as Mario kart really. Decent enough but I get bored of always feeling like I’m ‘chasing’ something when it comes to free mobile games and it’s annoying feeling like you’re constantly being pushed towards spending on in game purchases. Much prefer the ds and switch versions.
used to be addicted to the Simpson’s tapped out but I cheated and got unlimited donuts and money and ruined it for myself 
