Over 10 years ago the world of mobile gaming was totally different from today's. Still many (if not most) phones could run installable and built in games. Which were your favorite ones?

Let's say the mobile game is retro if released before 2009.

Last month my dad had a stroke. Miraculously he didn't lose much functionality at all, though he does have some minor cognitive issues that we're working on in rehab - mainly memory. Accordingly, we want to find some games he can play on his tablet to help keep his mind active and focus his attention. But the mobile game market is hard for me to navigate and sort through for what I'm looking for.

I need games that're about a dollar or less and don't have in-app purchases. Basically games you could give to your kid and trust that they're not gonna be psychologically manipulated into wanting to empty your bank card or something like that.

Brain teasers and simple puzzles are ideal for sharpening his mind but any game that's good clean straightforward fun will work. I don't think he's going to be able to handle anything with a whole lot of moving parts like an RTS right now, for instance.

I can't afford to spend much on this and I don't know what kinds of games will interest him most so I want to give him a lot of choices. I've already looked through a couple of the other mobile game rec threads on here and I'm checking out the games listed there, but I was hoping you all could help me think of some stuff more geared to my situation. Any pointers even just on where to go looking or what to google would be appreciated. Cheers!

Edit:

Thank you all for being so supportive! I've added a bunch of the games you recommended, and I also found a couple nice lists that I thought I'd add here for anyone else interested.

Short List of Totally Free Games

10 Completely Free Mobile Games

Stay awesome tildes!

I don't play mobile games very often but every now and then I want to load up something a bit more substantial than your average mobile game without having to log hours like Fallout Shelter. I played something called (I think) Pixel dungeon in the past that was a sort of roguelike and I enjoyed that. What do you guys play and recommend?

I had this game on my phone for awhile but only just started last night. So far I think it's neat what kinds of landmarks can be pokestops, like a little fountain by a restaurant or a very old building. It also reminds me of those pokewalker things from long ago, the ones that counted your steps. It also kills me when a church is a gym.

Now I'm not walking everywhere or buying plane tickets trying to do this but it's pretty pleasant so far. What are your thoughts, Tildes?

Edit: I took my first gym at a quaint little church and the Nidorino I left there came back about 6 hours later. There's more people playing this than I realized, also more churches lol.