Don't know if it was ever announced to be in development and existed in any form outside of being told there was going be 3 games, but would absolutely love to have seen what the 3rd Sonic book game would have been like. I still need to play the Black Knight game, but would absolutely hop on board the 3rd if it existed.

That, and would absolutely LOVE if Sega uncanceled the Riders series. Best racing game series to ever exists in my opinion. Too bad the 3rd game sucked so hard it caused the beautiful rose that is the Riders series to wither away.

So I have three different typ of games from the top of my head.

A game I know was a thing that got cancelled. Life by You I am so pissed it got caned. I was looking forward to it so so much.

Then a game I don't really know if it actually was a thing, I heard about it after it was cancelled, but I can't really find much about it. Is The Sinister Six it was apparently a game about the Spider-man super villain group of the same name, as they appertaining in Insomniac's spider man games. All I really remember is that you were supposed to play as the villains and it sounded good, I however only heard about it after it was caned so I really don't know much more about it.

And then there is this game that was never a thing, but an April fools joke in 2015. There would be a cross over game between The Sims and GTA. I got so excited about it, it still sounds like it could have been awesome.

Those are some different typs of cancelled games that I really miss.

I was ecstatic when Phantom Dust was getting a sequel and then I was mildly happy that it was at least coming to PC. I want more.

Super Mecha Champions on PC.

Yeah, it was a Gacha Battle Royale mobile port. But it was so fun to play. The community was fantastic, except the like 3 cheaters on perpetual ban cycle.

I loved the character design, and the mecha design. The graphics could age really well being cel-shaded/anime styled. And it was unique in its category, no other BR game lets you play as a pilot and call in a mecha, or battle a mecha as a pilot, or vice versa. And the best part was that the F2P economy was pretty good. Paid players got new characters and mecha a week or two weeks before paid players that haven't been playing the game. F2P Barnacle players could use currency earned in-game for characters and mecha and it would take maybe a week or so to get the amount needed. You didn't even have to win, you just had to play. It was great. The cosmetics were well designed too, mostly. Except that one Ventorus skin that made the extra hands a little too big and cover more of the screen than normal.

Sadly, the servers were shut down by NetEase, probably to make more server space for Marvel Rivals.

Hellraid looked like it was going to be an awesome spooky fantasy game but then they turned it into a shitty dying light dlc.

Donkey Kong Racing. Oh what could have been.

The Last of Us Factions 2, even though it never came out

There was this awesome cooperative programming game called Leap Day from SpryFox. You would login and set up your automated citizens, collecting items, combining items, items with people in neighboring sections to defeat a boss in the middle, but the boss could only be completed by using items from your neighbors. Over time you would gain money for items you brought back to your base and every minute the day on it would resent and everyone go out and collect the same items again. You would have to build and rebuild your area to make enough factories to develop what you needed. I don’t think I’m it justice. I miss it all the time.

This is before my time but I remember reading about a canceled movie tie-in game for Star Trek: First Contact.

GunZ

StarCraft Broodwar (need to make a Blizzard account now apparently)

Infinite Crisis. This was a MOBA based on DC comics. It’s the game that got me into the genre and had some very cool alternate takes on some of the DC characters. Sadly it had a lot of balance problems and other issues causing it to close down after only 6 months.

Steambot Chronicles 2 and Maximo 3. I can’t believe they never finished the Maximo story. It’s such a good hack and slash collectathon of the PS2 era.

True Fantasy Live Online. It sounded amazing.

64dd, specifically earthbound 64

Chromehounds.

C&C Generals 2, they got canceled and then made in to a mobile game. I considerd staying 10 hours in line to try it out at gamescom in köln 10-12 years ago, decided to get drunk instead.

Star Wars 1313 and Battlefront 3.

And for books it's the unfinished Republic/Imperial Commando series by Karen Traviss

Limit Theory. Quite the ambitious space simulator being developed by one dude. I recall seeing their dev log videos on youtube.