Games

Cell to Singularity is a great little mobile game that does have microtransactions but are easy to ignore/avoid. I played through it several times and may need to dust it off for another playthrough. Great music too.

Loop hero is really fun imo! Also solitarica

Exiled Kingdoms, its an older isometric 2D adventure RPG. Kinda feels like it would have been made 30 years ago for pc, but it was made relatively recently for phones. I don't think there was any micro transactions. It may have had an initial purchase price, not sure. That's usually what I look for in a phone game. The traditional model of buying a game and then just playing a game. No gross mobile game stuff.

Galaxy Genome, it's a space exploration game. Sort of a project to make a comprehensive 2D version of Elite: Dangerous. Or at least it started as that, I don't know if it has achieved and surpassed that by now. It was pretty far along last I played. And that was a while ago now. I kind of play games on and off for years, so that is mostly gonna be a running theme of all the games I post here. Games that you find yourself wanting to pick back up again, over and over.

If you don't mind a classic chess. Blitz/bullet/rapid/horde are different styles that don't take as long to learn enough to have fun. Chess puzzles or against the computer are available if you want to keep it strictly single player. Lichess for multiplayer or I like chess tactics pro for puzzles.

Crosswords, there are programs like alphacross that aggregate from other sources to try different puzzles to find ones that aren't too easy or hard.

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.

Hmm, I was gonna say moonshades, last time I played it there wasn't much for things you could buy. But when I look now, there is. So I can't say for sure how unnecessary any of it would feel now, but it wasn't necessary back when I played last. It's kind of like the old early 3D party dungeon/maze crawlers where you use the arrow keys to walk one "block" at a time. There is only 2 party members in this. So you still sort of get the group synergy stuff, but each character is a bigger share of the team power. You could do a tank/healer thing or magic damage/melee damage, or not have either one focus on anything in particular.

I hope it's still not necessary to buy anything, it was a good game. But the store is pretty comprehensive now, so that has me worried.

If you have a Netflix account, you can get Bloons TD6 for free on Android. It's fun and the microtransactions are completely unnecessary and hidden away. Beware it's a battery hog though

Also, if you like puzzles, look up the various variant sudoku apps from Studio Goya, particularly the one called "Cracking the Cryptic"

Antimatter Dimensions

Imagzle. There are "buy more levels" but there are plenty on the main one. It gives a picture, more or less, abstractly related to something. Art, movie, book, many random things

Cosmic Combo, an iOS port of Johan Peitz’ PICO-8 game Cosmic Collapse, is good.

Old School RuneScape potentially fits this description

Star command, anomaly, world of goo, EDGE, knight of pen and paper...

These are some good ones I got from humble bundle over the years but many are quite dated so not sure if they're still around. No BS microtranactions

Gubbins is a fun word game, it's a one time purchase and apparently part of the profits go to charity due to Hank Green investing in it in a creative way.

royal match has no ads at all, its pretty fun just gotta ignore the microtransactions which is pretty easy to do at least compared to other games

2048 but a version from F-Droid: https://f-droid.org/packages/org.secuso.privacyfriendly2048/

Walk master

I play chess, mahjong on mobile.

There's also final fantasy pixel remasters, Baldurs Gate, planetscape torment, shadowrun games and trials of mana on mobile too.

Out of the Dark is alright.

Gardenscapes is the original match 3 and build a mansion and is still my favorite. There are micro transactions to get additional power ups, but the fact that they are constantly updating with new seasonal events and you never run out of levels

You can get a port of space cadet pinball from GitHub!

Probably Scalak, a 3D puzzle game. It isn't foss and is paid.

Alto's Adventure is a pretty chill game to play when killing time. https://play.google.com/store/apps/details?id=com.noodlecake.altosadventure

I also like the "connect the dots" puzzle games, like this one: https://play.google.com/store/apps/details?id=com.playvalve.connect.dots

Neither game requires microtransactions for the full experience. They might have ads, but my adblocker blocks them if they do.

Emulating a Nintendo DS and looking for stylus only games is my recommendation. Games like Kirby Canvas Curse, Kirby Mass Attack, and Warioware Touched are fun.

Word Cookies. I absolutely love it. You can pay for things, but it is absolutely not necessary and is basically only if you feel the need to use boosts that allow you to cheat your way past the level. I think it costs $2 to go ad-free.

It does give you regular popups asking if you want to buy coins, which I admit is annoying, but they are unnecessary to enjoy the game. There's also endless opportunities to get coins and other boosts for free. I have something like 80,000 coins and dozens of boosts and other than the $2 to go ad-free, I've never given them any money.

You do have to have certain word skills to enjoy it as much as I do. If you're the sort who can crush it at Boggle, it's the game for you.

Emulation!