Free Android Games & FOSS ✅️ - no ads, no IAPs, no gacha.

This only kinda meets the criteria since emulators are available on the play store, though roms will have to be sourced elsewhere, but... 100% roms and emulators. The N64 content and earlier emulate really well on a smartphone, especially when paired with a bluetooth controller.

IIRC ever version (different language releases, etc) of every game for Nintendo consoles from when they first became a company through all of the N64 content is a grand total of like 20bg: each individual game is tiny, so you can easily fit all your favorites on your phone.

I'm not sure what the latest and greatest emulators are today, but when I dabbled into this stuff last time, there were free, no bullshit options.

Quick search reveals a couple communities for it here on Lemmy:

!emulation@lemmy.ml

!emulationonandroid@lemmy.ml

I'd hit the side bars of those communities and go from there.

Note: downloading roms you don't own the license to is piracy; and even if you do own the license, your ISP won't know that, so I'd recommend practicing some basic internet safety like using a VPN. Also, ad blockers are an ABSOLUTE MUST on any website that provides or directs you to roms, otherwise you'll have like 20 links on your page that all say "Download!" that will lead you to some flavor of shitware.

But yeah, if you want games without all the modern bullshit in them like ads and lootcrate gambling, etc, then what better option than games that were made before all that cancer existed?!