What if Alternate Reality had been able to keep going with their interlocking games? The games of the series weren't just following one another, they were meant to go together. You would buy The City, The Dungeon, The Wilderness, and so on. If you were in Wilderness and wanted to go back to town to sell, you would exit Wilderness via the city gate, the game would make a save, and The City would be able to load the save so you could sell your stuff at a shop there.
I'm dubious it could have worked at the time because technology was changing so fast, it would have been hard keep the first games working by the time the last parts came out. In today's environment, though, maybe....
What if Valve created Half-Life 3? Would it be good, would people praise it even if it sucked?
Would they have included a not-so-short video so you could catch up on what the story was doing twenty years ago?
What if E.T. the Extra-Terrestrial for the Atari 2600 was a good game?
Now now, we have to have IMAGINABLE what ifs!
What if nintendo started to allow its IPs to be used over multiple platforms and they do their own variation of a "gamepass" that works on pc.
Nintendo would be making vastly more money.