Another videogame I've been playing lately is Idle Heroes, which is an RPG for the phone. The basic premise is that your heroes auto-battle every second of the day. So you can close the app, open it ten hours later, and your characters will have earned a ton of EXP and gold. It's great!
My main beef with the game is that you can't pick and choose which characters you have. Characters are assigned randomly. I've had bad luck, and I've been stuck with a group of forest-based heroes. I need a fighter-type hero who can serve as a tank, but nope.
There is a "replace the hero" function which you can use, but all that does is replace one hero with another randomly-assigned hero. And to use this function, you need a premium currency. There's also a premium currency for leveling up characters, for summoning a specific hero, for equipment stones, and for summoning monsters.
So, yeah, it's a modern phone game with lots of micro-transactions and paywalls. I'm at the point where you basically can't proceed, unless all your characters are five star heroes, at max level 100, with max equipment. That's why I can't replace any of my forest heroes; getting a single five star hero is so difficult, you're basically stuck with the ones you get.
The weird thing is that I'm not even a third of the way through the game. How can there be so many levels left, when you basically need maximum everything to win a level? I'm told--and I can't confirm--that you can combine two five-star heroes of the same type into a six-star hero. That's probably the only way to proceed, but jeez. Getting a single five star hero is hard enough. Getting two of the same type, especially when the type is randomly determined? That's a rough paywall.