In order to revive a dead game you need the actual source code or you need to somehow reverse engineer an older version of the game in a very specific way that it allows you to hook it into a new server you'd need to set up and operate. One of the hardest aspects is the fact that most of the time the source code is missing or flat out locked away somewhere nobody will ever find it. Even then in certain cases the game may have some critical aspect that requires a central server to function. Take the image I'm posting with from a game called Zenonzard. Zenonzard can be revived as a card game, but because a major facet of that game was with its learning AI technology acting as both in-game partner and PVE enemy the full experience can never be brought back. Zenonzard in its original state is dead with no way to save it, thankfully the game itself is a functional card game regardless but it'll never come back as it was.
Some devs do make EOL plans though such as Capcom making Megaman X Dive Offline, which makes it so the later characters require progression to unlock as to not break the game's balancing but as it's an offline affair, co-op levels and PVP were both cut. Then you have cases like Avengers where Eidos is just going to leave P2P on and unlock everything for you, Multiversus where it's local only and you can only take home with you what you bought, or Knockout City which provided the tools needed for players to run their own servers for the game. It's a case by case basis and in most of those cases would need to be fueled by passion and napkin sketches because some facets and faculties may need to be remade from scratch.
>>431281 So fun thing about those old browser games, the files used for them were found to be stored in the internet caches of some people leading to private servers being able to be made.
