If you like the older Pokemon games and can get the ROMs on your phone, PokeMMO is really cool. It’s an emulator that turns the first 5 generations of games into an MMO where you can take the same character across each region.

There’s a handful of changes to the base game, but most are small: Berry farming is changed, there’s an Exp Share for EVs now, Sweet Scent is used to summon a 1v5 against wild Pokemon… There’s character customization… There’s some QoL stuff like shiny encounters having a sound effect and adding a confirmation box so you don’t accidentally flee, and the stats page for your Pokemon is way more detailed.

One time purchase:

• Peglin ✨
• Luck be a landlord ✨
• Forager
• Dicey dungeons
• Dead Cells (optional DLC)
• Bloons Tower Defense 6 (out of the way IAP) ✨
• Terraria
• 20 minutes till dawn (has a non premium option with some micro transactions)

Free:

• Antimatter dimensions (long idle-ish game) ✨
• Legends of Runeterra (just play the story modes) ✨
• Team fight tactics (cosmetics only)
• Plague inc (and probably rebel inc, but I haven’t played that yet) ✨
• Super Auto Pets (cosmetics and extra optional sets) ✨

Star on the ones I’d specifically recommend for casual play

@PlzGivHugs Unciv, neat open-source turn-based 4X, obliviously inspired by the Civilization series

Monument Valley and Gorogoa are both excellent and free of nonsense.

Both are available on mobile and Steam. Gorogoa also on GOG currently 70% off.

Meant to link monument valley 2: https://www.monumentvalleygame.com/mv2

A Dance of Fire and Ice is an incredible rhythm game that you buy once and that’s it. I think there’s an expansion pack but it’s a single purchase. Whether that’s your idea of “casual” really depends on what you like. You can always play chill low difficulty levels when you need to zone out, and high difficulty levels when you want a challenge. It can get stupidly hard.

You can try a demo online at that link. It told me webgl wasn’t supported on mobile, but it worked pretty well for me just now on firefox, even if it was a bit laggy. It should work fine on PC.

I pirated it on PC after my kids told me about it and ended up buying it three times on Steam and twice on mobile. It’s just that good. I’ve built a custom digital drum to play it and I’m now making a custom MIDI controller, so we’ll see if that does better when connected to the game.

The game works as well on mobile, if not better because the touchscreen is so responsive.

In my experience the relatively small selection of the F-droid store is full of these type of games.

Troll patrol

Sudoku

Unciv

Shattered Pixel Dungeon

Pirate Solitare

…just to name a few All full versions, no ads or premuim options. Love F-droid, its a shame the selection is quite small.

The website https://nobsgames.stavros.io/ helps surface these, and let’s you filter out based on different things.

One that I like in particular is Gauguin. It’s a Sudoku-like with different math-y rules.

Anuto TD is a tower defense game that is also really good, but not so low stress.

Lichess, if you’re into Chess. It’s a great, no compromise, high quality app. Stressful if you get too worked up about competitive, but puzzles are at least relaxing.

A couple that I like:

• 80 Days - it’s not free but I think it’s worth it. It’s a sort of steampunk version of Around the World in 80 Days where you have to plan your routes, and buy and sell things in different cities to make money. The main gameplay is sort of choose-your-own-adventure events that happen during travel and in different cities.

• Card Thief - I just started playing this recently. It does technically have a microtransaction but it’s more like, they let you play for free if you don’t mind waiting for chests to unlock, or you can buy the game to bypass this. The main gameplay is sneaking through dungeons represented by a 3x3 grid of cards randomly drawn from the deck; collecting treasures and avoiding getting caught.

Beleentoro Pro might be something for you. Basically a chill factory game, which I enjoyed for a long time. Other games by the developer Yiotro might be worth a look too.
There are also free versions of most of their games available, with ads iirc (not sure, has been a while). But if you don’t want the ads: the pro versions are really cheap. One time purchase for everything.

Another idea I have a puzzle game called: Mekorama by Martin Magni. The last time I played you got an option to pay what you think the game is worth at the end of the game. But you don’t have to.

Mini Metro by Dinosaur Polo Club is also really good, but comes with a purchase.

If you like tower defense, Bloons TD 6 by Ninja Kiwi is a must have. Comes with a purchase and has the option of microtransactions for cosmetics, but you can get those by playing as well. More importantly, it’s tons of fun.

In case you’ve got a Netflix subscription, check out their games. They have lots of games in their repertoire which you would have to buy if you went through the App/Play stores. (Bloons TD 6 should be included there for example.)

Edit: corrected Bloons TD 5 to Bloons TD 6.

Andor’s Trail, it’s barely recogniseable as a “phone” game, other than that it does indeed run on phones. I don’t remember if it had ads or anything, been taking it from phone to phone for over 10 years now. I don’t think it had ads or anything. It’s open source, but has a pretty consistent feel despite having like 50+ contributors so far.

It’s an adventure RPG. The low level experience might be best with a bit of grinding, but… casual grinding… lol. I kind of just wander around collecting “meat” until I feel strong enough to leave the areas near town and set out on the rest of the adventure. But there has been alot more work around town since the last time I started a new character. So it might feel more natural now.

I’m enjoying isle of arrows right now. Tower defense but instead of having a set map and same towers you get to draw cards and have to make do with what you get. Some cards give you pathing for the mobs, other expand the buildable area, others give you towers. Simple and fun. Game pauses between waves so you can take as long as you want to prepare.

Sky: Children of the Light

You get to run/fly/swim/dive around and explore several mostly chill realms, helping out “spirits” and collecting light (one kind for currency, another to increase flying ability), and optionally interacting and cooperating with friendly randoms from around the world. There is a story to it which I won’t spoil, but there is always more to do even after playing through it.

There are zero ads.

There are some optional transactions, but they aren’t pushed constantly (there are changing “seasons”, and you can buy a pass for each one which will give you access to special cosmetics and the in game currency to buy them with, but there is plenty to collect without it).

Seasons also repeat (not exactly as they were, but the spirits from them return and their items become available again) so if you missed something the first time around because you didn’t have enough in game currency, or you took a break from the game, you’ll get another chance at it (I also think items that were initially only available with the pass you buy for real money, later become available for in game currency).

Keeping that in mind, you can grind as much or as little as you like, and there is also a limit to how much currency you can collect a day, so there’s only so much grinding you can do if you are so inclined. If you’re not that bothered about buying all the items, you can take a really relaxed approach and just play through the tasks and explore at your own pace (even learn how to play an instrument lol).

The first time I played it a few years back, I didn’t really “get” the game, or think to look up any information about it, so was just randomly flying around and getting confused and frustrated when things were a little less chill at points, so I quit. But a few months ago I decided to give it a second chance and having actually taken the time to understand what is going on in the game, this time around I’m enjoying it a lot more.

Cardinal Quest 2, it is possible to spend money, but honestly spending money would be worse than earning the stuff yourself. I still probably gave them some money, since I think the game was free. You don’t have to have played Cardinal Quest 1, it’s pretty story light. Kind of like playing Diablo 2 if you never played Diablo 1. Kinda the same game as the first with much better execution after learning some lessons. The game itself is pretty easy, but there are optional challenges you can take on that can be as their name implies. Lots of replayability as there are many character classes and 4 different stories. Over time you’ll likely want to beat each story with each class. Mostly cuz it keeps track, lol.

Grim Quest and Grim Tides. Two games by the same person. I haven’t played Grim tides yet, but it’s also free. Grim Quest is not a particularly large game, but I’ve still managed to play it over many years. I did a full run of each difficulty one by one. There is a bit to learn before it feels easy and casual, but it does get there. To be fair, I try to play it without dying. If I let myself die, it would be alot more casual even from the start. Dying is not heavily penalized on default settings, but you can alternately choose to play hardcore. Otherwise dying usually just means you gained less money for that run, and didn’t make the game any harder. The game only gets harder when you successfully clear a dungeon. You can also just exit the unfinished dungeon without dying and keep most of what you have acquired so far on that run, minus a small fee for quitting the dungeon.

There are preset difficulty options, but you can also craft your own custom difficulty. There are things you could spend money on, I think it may have started out with ads. But I consider games with ads that you can pay to get rid of as basically a free demo, and getting rid of ads is the purchase price if you like the game. So they don’t deter me if they don’t basically break the game to add ads to it, or affect the flow of the game whether the ads are there or not.

Slay the Spire has a decent mobile version. Not sure about the casual part, but at least it’s turn based