Yume Nikki has NASU as a small mingame you can play when you are awake.

Really cool list, I love the idea!

If I may contribute a bit here:
Stardew Valley has Journey of the Prairie King
Call Of Duty: Black Ops has Zork
Animal Crossing (GCN) has tons of NES Titles
Smash Bros Brawl. and Smash for Wii U have “full game” trials under a 5 minute timer
Celeste has Celeste Classic
Day of the Tentacle has Manic Mansion
And finally Homefront: The Revolution weirdly has TimeSplitters 2

Came in to say Stardew Valley has an arcade game within the pub. @Iru beat me to it lol

The Wii version of Indiana Jones and the Staff of Kings includes Indiana Jones and the Fate of Atlantis.

Thanks everyone for the great suggestions! I know this is going to be a humungous list eventually.

@MPK92 if you can find me a list of the Yakuza games and what video games you can play in them I'll include them!

@DemonAndGames I've never even heard of this and I LOVE when the game-within-a-game is fictional and part of the in-game universe <3

@Iru Thank you those are great suggestions! I wasn't able to find a definitive list of what's available in Animal Crossing; if you can find that I'll update the note.

@FallenGrace I'm still impressed you knew! :)

@Penumbra So the intention is to include games where you diegetically, as a character in the game, are playing a video game. I haven't been able to figure out if Indiana Jones is set up that way or it's just a separate title included with but outside the main game... do you know? Either way thanks for the suggestion!

Oh yeah and @Iru the same for Smash Bros; are these actually playable within the main game?

@cowboyjosh Oh, then my suggestion doesn't fit because the protagonist doesn't play the game, it's separate from the main game.

Would you count Minesweeper as a potential game within a game? If so, you can play a full round of Minesweeper on one of the days within A Mortician's Tale.

@Drax yes! That's perfect!

Commander Keen has pong on his smart watch, the 4th game specifically, not sure about the others.

The Final Fantasy XV gang all play a gacha game in their phones but it's not playable. There are playable pinball/pachinko like game cabinets named Justice Monsters Five at the inns.

Jaiden from Heavy Rain has a squash like game on his AR interface.

There's an Earthbound clone in Eastward

System Shock 2 has a portable game console with games you can find in the game world, in System Shock 1 you can find games that can be played directly through the HUD from your augmentations.

The Nameless Mod has a built-in Tetris, Pong or Breakout in some of the terminals (also an actual IRC client, not a game but I think it's cool)

@Jackier great suggestions, thanks! I'm drawing an arbitrary line and including only "video" games so I don't have to include the many implementations of bowling, darts, fishing, etc, so I'm not including FFXV. But you got the earliest one so far with Commander Keen 4; I actually beat that game as a youth and forgot all about it!

@snak Added, thanks!

@cowboyjosh About the Smash demos, they are actually the full games in its entirety. you can manage to play the entirety of within that 5 minute limit, however they are accessible by a menu and not in the story campaign or actual gameplay if that makes sense. So it’s a stretch of the rules. You can see more about them on the wiki here: https://www.ssbwiki.com/Masterpieces

And for Animal Crossing, I found a similar site could be definite or not. We can stretch this definition as there is an i game NES emulator that Nintendo made for the game, entitled acNES. Any NES Rom if modded in can be fully playable inside AC!

The pinball game in ffxv is played through an arcade cabinets in game, I think it counts but it's your list.

Also, in Machinarium there's a hint book item that requires you to beat a short Gameboy like Shump level to unlock it every time.
Not sure if it fits the theme.

Great list idea!

@Jackier I re-downloaded FFXV and played some Justice Monsters Five and you know I think I agree with you. I thought you meant mechanical pinball machines but these are more like big video poker machines where they’re a video game emulating a mechanical one.

No More Heroes 3 (Deathman)
Sludge Life (Crypt Creeper)
Yakuza 0 (Out Run, Space Harrier, Super Hang On, Fantasy Zone)

@Sibus great suggestions! Added them all!

Just saw this, I made a comprehensive list of NES games in Animal Crossing (GameCube) here: https://www.backloggd.com/u/thealexmott/list/every-nes-game-in-animal-crossing-gc/user/detail/

@thealexmott amazing!! I'm going to update this tonight!

Fully lifted like a dozen more of these from this great list. Thanks @tendog !

tomodachi life has 'tomodachi quest' https://youtu.be/CU6QBAPrvNg?t=728

@Gliscor that’s perfect; thanks!!

Feels like a stretch, but one of the stat building mechanics in Persona 5 is that you can rent video games from the store and play them at home. The games aren't fully playable but will basically have a QTE event thing for each one that you have to pass in order to "beat them"

Like a Dragon Gaiden is gonna include the arcade games Fighting Vipers 2, Daytona USA 2 (rebranded as Sega Racing Classic 2 for this game), and Flicky, alongside playable master system games Alex Kidd in Miracle World, Alien Syndrome, Enduro Racer, Fantasy Zone II: The Tears of Opa-Opa, Galaxy Force, Global Defense, Maze Hunter 3-D, Quartet and Secret Command
there might be more but these are the ones i'm aware of

@TimAlien nothing wrong with a little stretch; I'm going to add it for now. I've got a P5R save with like 30 hours on it and the game is still on gamepass so I'll redownload it and try the activity and see if it feels like it fits. If it was just a cutscene or whatever I'd probably pass but the QTE sounds like it makes it more like a real game.

@Reddish the LAD games are gifts that keep on giving for this list. Thanks for listing everything out so I don't have to look it up haha!