Shattered Pixel Dungeon. If you like Roguelikes.

Knights of the old Republic has been on there for a while.

Emulators.

Slay the Spire.

Vampire survivors is one of the best time killers. Slay The Spire is also fun.

There is a curated list of "no-bullshit" mobile games, without microtransactions and all of that horrible stuff: https://nobsgames.stavros.io/

My favorites so far:

• Monument Valley 1+2
• Riptide GP: Renegade
• Badland
• Galaxy on Fire 2 HD

SLAY THE SPIRE!

shattered pixel dungeom

Games with roguelike metaprogression:

• Vampire Survivors: Practically an idle game. All you do in this is control your hero's movement around a sea of monsters and your hero automatically attacks them. Surprisingly fun and strategically deep. Battery killer
• Slay the Spire: card collecting strategy game
• Bloons TD 6 (requires Netflix): Pop Bloons with monkeys. Battery killer
• Into the Breach (requires Netflix): isometric strategy game from the same devs as FTL: Faster Than Light. Big emphasis on using near-perfect information to solve tactical fights like they are puzzles.

Puzzle games:

• Any of the variant Sudoku apps from "Studio Goya" on the Play store. These are the official apps of the Cracking the Cryptic YouTube channel. Handcrafted puzzles tend to have a very interesting solution path that requires you to develop logic skills.
• The Room. Play as Tommy Wiseau as he uncovers an Eldritch mystery by opening puzzle boxes. Very satisfying animations, neat story
• Cultist Simulator. Honestly idk what to call this one but "puzzle game" kind of fits. This is a really fun game but requires a while to get a hang of. In fact the fun of the game is learning the game mechanics, since nothing is explained except through cryptic hints and riddles. The writing is incredible but you will probably lose a lot as you get the hang of it.

Other stuff:

• Eternal Card Game: I'll be honest, I haven't played this in ages, but I remember it being a better MTG clone than MTG arena. The mechanics are almost the exact same feeling as MTG, but more adapted to the digital medium. Has some pay-to-win mechanics and microtransactions but honestly the pricing felt pretty fair to me and it's not super in-your-face with it.
• RCT Classic: Rollercoaster Tycoon 2 mobile port. It's not as good as OpenRCT, but it's still a lot of fun.
• OpenTTD: Transport tycoon deluxe mobile port.
• Papers Please: Glory to Arstotzka!
• Townscaper: not really a game as much as an arts and crafts kit. You get a tile-based map and wherever you click it fills in a tile. Depending on how you fill in those tiles, they look like different little buildings, gardens, etc. really cute game with no stakes.
• Mindustry: minimalist Factorio clone. Controls can be challenging on mobile but it's still fun

Slice and Dice is a good rogue-like dice builder with no bullshit.

No ads. No DLC - there's a demo game and full version. And the mechanics are solid with no grindy bits.

Monument valley is pretty good and has no ads or micro transactions

Hoplite is the one. No ads, great gameplay, no addictive pattern.

Probably not what you're looking for but this is my favorite time-waster.

https://abagames.github.io/crisp-game-lib-11-games/?pakupaku

Decidedly not arcade, but I absolutely love Shattered Pixel Dungeon as a phone timekiller.

Monument valley

* Starts shootin corrupting wand *
Shattered Pixel Dungeon gang rise up!

Slay the Spire.

Geoguessr.

Rollercoaster Tycoon Classic.

Slice & Dice is the best game I've ever gotten on my phone, I bought it over Thanksgiving in 2021 and haven't stopped playing it since. It's similar to deck builders, but dice based.

It's $7 on mobile, but has a good free to try demo. So you can see if you like it for free. It's also available on Steam and itch.io

The game is still in active development, but the dev only releases updates every 1-1.5 years. The updates are absolutely massive though and add a ton of content.

If you're into Pokemon and have access to the GBA/DS ROMs, PokeMMO is a great emulator that adds online MMO features to the first 5 generations of Pokemon. You can take one character across all 5 regions, and there's tons of QoL features.

Into the Breach.

If you like roguelike card builders, Dawncaster is great

supertuxkart SuperTuxKart (A 3D arcade racer with a variety of characters, tracks, and modes to play.

The older Pokemon gameboy games (using emulator).

The Room series - puzzle/mystery style.

Bloons TD? I whike away time on it occasionally.

Bloons:td6

I enjoyed both Monument Valleys, the Room series, and Downwell.

If you like twitchy reflex killers, two oldies-but-goodies from Terry Cavanaugh: Super Hexagon and VVVVVV.

Fun chiptune soundtracks, minimal graphics, and so much "I died already? Okay just ONE MORE try and then I really need to get some work done. ARGH - okay maybe ONE MORE try...." And when you finally succeed the dopamine is second to none.

Does it have to be arcade?

I love "papers, please".

If you're in to a bit of a challenge then "Flow". There's many copies but I always played "Flow Free" for killing time.

Chess (on Lichess, either browser or app)

Got time? Practice openings or play online.

No time? Play 1 minute games online.

Inconsistent time (have to go any moment) or just casual? Practice puzzles.

Sky Children of Light

Rusted Warfare

Endless Sky

Lichess. It's also completely free.

With a little bit of know-how, you can get Balatro running on your phone, and Balatro is amazing.

To do it, buy the game then follow the instructions at https://github.com/blake502/balatro-mobile-maker

You Must Build a Boat and Triple Town are simple but excellent. Slay the Spire is incredible - can't recommend it enough.

Machinarium

I do chess puzzles on lichess

AM2R a.k.a. Another Metroid 2 Remake It's a fan game of the 2nd Metroid game, and is considered one of the best of the series, even though it's not an official release. It's more like Super Metroid than the Gameboy title is. You'll have to search around a bit due to Nintendo's D&C, but it's not hard to find (the internet archive has recent versions).

Minecraft It's a good port, but probably best played with a gamepad &| tablet.

Portal Knights A minecraft-like voxel game with more satisfying progression and combat, but less creative freedom. Plays well on newish devices, epsecially with lower-quality settings.

Terraria It's a great game all-around, but harder to play on mobile than PC.

Emulation This goes without saying if you like retro gaming. The best emulators I've found are the .emu apps by Robert Broglia. They can be bought from the play store, or obtained for free at his Github page. If you like original Playstation games, get the Duckstation emulator (produced by another dev.).

Dead Cells and Peglin

Slice & dice stole all of my free time for a while. I definitely recommend it.