Lately I been thinking that most of the "Free to play" games that I come across are commonly online mutiplayer and always have you connect to a server saving and tracking your info. Now I was curious if there is any console only games that are free but not multiplayer. (Yes that means pc as well) Also no visual novel "games" either.
On consoles, I doubt it. That would mean the developers had to pay to get their game on a platform, but had no way to see anything of that revenue back.
On PC and mobile, there are quite some.
On PC:
-openTTD: transport tycoon deluxe, but open source. You might want to use the original files for classic graphics, but if you've never played the original you probably won't even notice the difference
-openRA: like the above, but for red alert
-Trackmania Nations forever: a free racing game
-unreal tournament: I haven't followed the progress in over a year, but aside perhaps a subscription to epic's account, I can't but assume that it's still completely free
-dwarf fortress: old, but a classic
-path of exile: diablo 2 clone that's still widely popular
-daggerfall. so basically the first version of skyrim
-Simon Tatham's puzzle collection: a bunch of simple but incredibly addicting puzzle games (note: perhaps even better on mobile)
Mobile often has a tendency to put adds in things, but there are more than a few that don't interfere when you disable wifi. I also found out about "appsales" recently. It tracks and shows discounts and temporary free games. It's almost absurd what kind of great games are being given away nowadays (perhaps it's expired now, but I just got an actual "Ori and the blind forest"-clone called Rima...and the graphics are actually as impressive).
-infinity loop (note: that's with that horizontal 8-figure): calming rotation puzzles
-Onirim: a solitaire card playing game. The base game is free, and incredibly addicting (the expansions are worth it and almost free, but again: the base game gives you more than enough)
That's all I can think of right now...