Ask Lemmy

There are many great Indie Games. My far favourite are the ones by 'yiotro' which seems to be a single (Russian?Ukrainian?) developer. Each is some kind of strategy/simulation mix and very cheap with simple graphics but a lot of depth. I discovered his work from seeing Antiyoy which either is so old that I got a demo of it in a ~2002 gaming magazine, or a copy of that old game. Just amazing fun all around and the only reason I don't have any of them on my phone right now is that I can't stop playing if I install them (similar to Unciv and Shattered Pixel Dungeon, both FOSS and excellent choices that were mentioned already).

Breakout 71. I could play for 30 seconds or 15 minutes. No ads, lots to unlock. Really like this one.

https://f-droid.org/packages/me.lecaro.breakout

Others have Mentioned Shattered Pixel Dungeon. Love that one too.

Outside of emulators and other similar apps, there are some games that have decent mobile ports. Some of the good ones I know of are:

Lego Star wars: the Complete Saga, which as far as I can tell, seems mostly identical to at least most of the other versions but it lacks all of the co-op/multiplayer components. I did also see some minor graphical glitches but they didn't effect gameplay.

The 3D remake of Final fantasy 3. It seems identical to the PSP version but it's obviously running at a higher resolution and possibly a higher frame rate as well.

Bloons TD 5, other users have mentioned 6 but 5 is also good too.

HamSandwich, which is not available through the Google Play Store, so you may soon be stuck with the browser version when Google's changes to side loading take effect. Also, I recommend using either a keyboard or a controller, as the touchscreen controls are not that good.

The Enchanted Cave 2, the first one is also pretty good too but 2 has a lot more content and is a much better game all around.

I know that a lot of people have issues with games that have MTX, but I will defend these games if they are actually good and I can play them without feeling like I'm being force to put money in. Here are some of the games I can remember:

Honkai Impact 3rd, I haven't completed the story yet but I've played up to the end of chapter 28 of part 1 and I haven't had to put a single cent into the game. My only issue with this game is that, while the game does have keyboard support and the keyboard controls are decent, it doesn't have controller support for some reason.

Bloons Monkey City, this game is basically just Bloons TD 5 but with a city building mechanic and some online components.

The Walking Zombie 2: Shooter. This ones a bit weird but I've been playing this occasionally. It's a pretty decent FPS that takes at least some inspiration from the Fallout games. It's not a masterpiece by any means but it still seems worth mentioning. I just wish it had keyboard and mouse support.

Swordigo!

I haven't seen it mentioned yet but I would add the mobile port of Wingspan.

Backpack Battles

Very fun strategic game, there are MTX in the game, but they're not necessary to play in the slightest.

I have bought a few things to support the Devs though.

I found Gorogoa pretty interesting.

Animal Crossing: Pocket Camp went paid about a year ago and there are no MTX or ads anymore. You can also take a look at Epic, they offer a mobile app with giveaways of paid games just like they do on PC.

Puzzle Heros rpg - this is a turn based match 3 game with diagonals and a time limit to match as many tiles as you can, this powers up your colour coded heros and you use them to defeat/harvest food based enemies to stock your food stalls. Stalls make money, money levels up heros, etc.

It's a 'reskin', albeit a very minorly changed one, of Match Quest, and the art/design is all really well done in an old school 8bit pixel style, with some really beautifully done layered scenery.

It gets a bit grindy and will take forever if you want to win every hero and level them all up to max, but as a casual game to dip into a few times a day to collect profits and loot old levels, and then spend twenty minutes or so playing levels, it's very fun.

I also recommend Flappy Dragon. It's a resin of the bird game, I think, idk I never played that one. The physics is fun and well thought out for each dragon and the dragons all have really nice designs.

Oh and it's probably been mentioned a ton on this thread already but Simon Tatham's Puzzles is a fantastic app full of puzzles that can be played offline.

Both KOTOR games have mobiles released that are pretty good

Space flight simulator is pretty fun

Most games on Apple Arcade is proper games.

Game Dev Story was a lot of fun.

I play territorial.io and geoguessr

Mecharashi has had me kinda hooked lately. It's a mech builder with turn based squad tactics combat. It's got gacha elements but I haven't felt the need to spend any money. Free rewards have been plenty to get the pilots and mechs I want. It's also a noticeably crash free game. I often swap between apps, changing podcasts and whatnot. This makes many games I play crash or return to the login screen, but not this one. Highly recommend.

Vampire Survivors is great!

I like the board game Risk on mobile, and Lichess.

https://sudoku.coach/ is installable as a progressive web app and is probably the best sudoku app I’ve encountered. Extremely customizable and good for learning new solving techniques

If you like incremental games, the Kittens Game by bloodrizer is awesome. Free website, or like a 3 dollars one time payment for the app.

Auto TD https://f-droid.org/packages/ch.logixisland.anuto

Luanti

Ace Attorney I believe had a very good mobile port.

One I’ve been addicted to, and have spent no money on, is Zenless Zone Zero. Gacha game with action-style combat using dodges, parries, and flashy effects. In some ways a cool demonstration of what phones can render now. Very much depends on what your gacha/FOMO resistance is.

Chess.com

Plenty of bots to get my buttons kicked in chess.

Infinitode - a tower defense game with a lot of meta progression

I think no one mentioned these yet: My favorite tablet games are the ports of old BioWare classics like Baldur's Gate 1+2, Icewind Dale, ... Excellent ports imo, bur I did play them on a 10" tablet, I wouldn't try to play them on a phone. https://www.beamdog.com/games/

Swordigo

Recently I really enjoyed Acecraft which is a gatcha bullet hell with cuphead art style. Its really charming and very much skill based to a point. The only negative is this constant clicking on shit to collect all of the coin garbage which eventually made me quit it but it was fun for a while.