The problem is more that many of the open source game engines aren't complete: features are missing, bugs not present in the original, etc.
These sort of projects tend to be pretty large and also fairly binary: either it's complete, useful, and playable, or it's not (yet) complete and it's unplayable and useless. There's a bit of grey area, but a lot less than many other projects. You can get away with "small implementation of X which slowly accrues features over time" with many projects, but a lot less so with reimplementation of games.
Everything is "binary" if you choose an arbitrary cutoff point.
Your example of ScummVM is a bad one: in ScummVM there are games that show nothing but a title screen, games where about half of the game works, games that are completeable but are lacking some aspect (e.g. music/sound effects/animations), games that are perfectly playable and completeable, and even games that have improvements upon the original games. The whole spectrum is present in ScummVM's engines at almost any point in time, as there are new engines constantly being added and others perfected. A game that's completeable but lacks music, for example, is certainly not "useless".
The fact that many of these engines are not (yet) complete is certainly not exclusive to game reimplementations. There's hardly any open-source project or game that declares itself "complete"
If any, it's good to have working WIP projects and reimplementations for games such as Resident Evil so they don't require emulation any more and thus they could run fast as hell on an Atom netbook.
I never said that's not the case.
It can be, because unless the game comes with all its own assets, it can't be a friction-free install for the end-users.
You can't expect to get the success of OpenTTD if you're unable to put the game on steam, and you cannot put it on steam if it won't run without the original game (which won't be on steam).
There other question of successfully cloning a game is "Will we ever be able to replace the requirement of needing the original game's files?"
With 2D games the answer is almost always "Yes, we can sooner or later have replacement 2D assets".
With 3D games you can forget about it; the effort and skill level is too high for volunteers to make it happen.
Not necessarily true. I can churn out game-ready 3D assets pretty quickly and I can't draw anything 2D at all. There's a lot of tools for 3D modelling and texturing that can provide some sort of automation to a degree (e.g. Houdini or even Blender's geometry nodes for procedural stuff [landscapes, mechanical stuff], Substance Designer for procedural materials, Mixamo for premade animations for virtually any scenario that you can simply attach to your models etc.). AFAIK there's nothing like that for 2D.
2D, while maybe fun to draw on a piece of paper, requires a lot of painful manual labor when working with games, e.g. you need to draw all animation frames separately instead of simply keyframing some skeleton as in 3D. Just imagine the process of changing a simple thing like a piece of clothing on a character.
This is really not true for most 2D games. For something like OpenTDD where the art is mostly functional and replacting it will still give you about the same experience as TDD, sure. For something like a Point & Click adventure? Nah, the art and scripting is the game, you might as well create a completely new game at that point. The distinction really has nothing to do with 2D vs. 3D.
A good game engine with good tools can save users who want to write that type of game a lot of effort. You shouldn't have to write collision detection algorithms to give the user a sword/gun/magic spell.
Looks like some of the original Monkey Island games were taken off the site and replaced with remakes, much to fans' dismay. I suppose there are other ways of tracking down the originals.
Har, har!
> some of the original Monkey Island games were taken off the site and replaced with remakes
MI and MI2, replaced with a 'Special Edition' which does include 'classic mode'.
Industry is not ready for leasing the assets to the end-users. Yet, I hope.
I think the reason for this is something you haven't considered: OpenTTD is extremely repayable, long-term fans of this game put thousands of hours into it. An old Point & Click adventure? Long-term fans might replay the game a few times every few years, but I don't think those sort of games will ever inspire the amount of invested effort that OpenTTD can.
Or consider Morrowind, closer to a Point & Click in concept (the art and scripting is a big part of the draw), but known to be a huge time sink that people can easily put thousands of hours into. And again, you see a very high level of investment from the community. Lots of total graphics replacement mods, mods that add huge new levels dwarfing the original game, etc.
These sort of projects tend to be pretty large and also fairly binary: either it's complete, useful, and playable, or it's not (yet) complete and it's unplayable and useless. There's a bit of grey area, but a lot less than many other projects.
Getting to this stage is often the biggest hurdle for these projects, not the lack of free resources.
But then the question is: Why not use the original game with ScummVM, DosBox or a VM (with whatever OS necessary)?
Isn't that an apples-to-oranges comparison?
Both games have graphics; you could substitute user graphics with the same semiotics, for the same objects into Morrowind, while retaining the same game feel, just like they did in OpenTTD.
Morrowind does additionally have scripted scenario dialogue and descriptive text. But you're picturing the wrong thing if you're picturing a need to substitute entirely custom scenarios. Instead, picture "paraphrasing to avoid copyright." Plagiarism isn't illegal; only literally republishing the text of another copyrighted work is. A hypothetical open-source Morrowind project could convey the same scenario with merely different prose — the same as they could convery the same object assets with merely different artistic direction.
And not only this, there are various graphical user mods to do just that, which someone bundles up into a modpack every few years
Clones would be Bombermaan, Secret Maryo Chronicles, Freeciv, Pangzero...
(IIIRC minus the music and cutscenes, which you can import from the original games)
> The OpenRA game engine is free software released under the GPL3 license. The OpenRA mods require files from the original games, which are used under the license granted by the C&C Franchise Modding Guidelines. These files are not covered by the OpenRA license, and you will be prompted to download or copy them the first time you run a mod.
> EA has not endorsed and does not support this product.
[0]: https://www.openra.net/download/
[1]: https://www.ea.com/games/command-and-conquer/command-and-con...
imo that’s the “problem” with most of the open source game clones. They are just the barebones engine where you need the original files. Which of course doesn’t sound like a big ask especially if it’s an older game but still additional extra steps that makes the users job harder. And also makes the official distribution of the game impossible. See how OpenTTD is available in one package on Steam [0]
0, https://store.steampowered.com/app/1536610/OpenTTD/