Sometimes, a game gets ported to multiple platforms; in the past, many CRPGs (and some other games) got ported to different home computers (yes, even Dragon Quest and Final Fantasy got MSX releases in Japan), while in modern times many games get released on both PCs and consoles, not to mention that there's different PC OSes and multiple consoles out there.

While it is definitely a good thing that more people are able to enjoy the games, sometimes there are differences between the versions (especially back when games got ported to different home computers), and every now and then, at least one version of an otherwise good game ends up coming out bad.

Here are some examples:
* Bard's Tale series: The Amiga versions have major bugs (in Amiga BT1 and BT2, Bards get extra attacks but Warriors do not), and the 16-bit ports (DOS and Amiga) of Bard's Tale 3 are just bad (monsters never use breath attacks or inflict status ailments, stoneblade doesn't work, harmonic gems are rare to the point of being frustrating (instead of being arguably too common as they are in the 8-bit versions)).
* Ultima 5's NES version is *really* bad, kuso-level bad, to the point where it's borderline unplayable. (They tried to remake it in an Ultima 6-like engine, but the NES can't really handle that, and the developers didn't really know how to develop for the NES.) (Ultima 3, 4, and 6 all got decent console ports, at least.)
* Might and Magic 2's European SNES release is incredibly buggy, while MM3 SNES, while quite playable, is unfortunately slow, and a bug makes one of the casting stats much harder to increase.

So, what other good games are there that have bad versions?

(Please don't bring up the Infinity Engine games in this topic; I would rather not have this topic devolve into an argument about them, and I can forsee that happening, so I am asking you to please not.)

There are the terrible censored versions for Germany (e.g. you don't kill humans in Command and Conquer or Half-Life, but robots; no swastikas in the Commandos games). Also horrible dubbing in some games (e.g. Starfleet Academy)...bad translations are another issue for many games in general (haven't yet played it myself, but the original English version of Pathologic is supposedly incomprehensible at times due to the garbled translation).
Can't comment on console versions, since consoles are below my notice.

The SNES port of Doom. I can't watch a playthrough of that because it feels like I'm going blind. Cities: Skylines for the Switch. Devs threw in the towel, which means no performance tweaks and no DLC. The Outer Worlds for the same console. It runs worse than the PC port, if you can believe it. The DS got a port of the first three Sonic games. The framerate was so bad I thought I was watching a Powerpoint presentation.

That pretty much applies to darn near every "mainstream" / "triple-A" game over the past fifteen years that was first released on a console and then back-ported to PC. No, I'm not saying "every" game over the past 15 years. But a pretty large majority of the most popular games from 20009 - 2019 were highly optimized for consoles, with PC as an after-thought.

Most common issues on the PC side were frame-rates locked at 30 fps, limited-to-no resolution and graphics adjustments, and limited-to-no controller/input remapping. It's only been within the past year or two that we've finally gotten a majority of AAA games that are built first on PC and then side-ported to consoles, instead of the other-way around.

My friend used to own the SNES port of Street Fighter Alpha 2, since he didn't own a PS1 at the time. It has muffled sound, and down-scaled sprites (Saturn and PS1 are not perfect replicas of the arcade version either, but they were less noticeable ). There is also load times at the beginning of a match, which is unusual for a cartridge-based game. That being said, it was surprisingly playable.

I forgot which version of Lion King it was, genesis / snes, but I had to stop playing because of how the music was butchered in the first level (which to this day remains my favorite level from any platformer).

Upon looking it up, it seems it was the genesis version with the weird tune. This is what it is supposed to sound like. It's not just the sound quality, the beat is somehow off as well.

A while back I bought the PS3 version of Rainbow Six Vegas and I couldn't believe how lowres it looked compared to other games on the PS3 and looks awful compared to the PC version (maybe 360 too but I don't have that one).
It's almost like they made a PS2 version on the PS3.

Pretty much any Atari VCS arcade port. :)

My childhood was all about being excited of getting a home system port of a great arcade coin op game, only to be disappointed how poor the port was. Like the Amiga version of Afterburner, what the heck was that? Even the music was shit. (That was the Activision version, later I've learned Amiga got another port of Afterburner which was much better apparently...)

The original arcade Afterburner (and Afterburner 2):

https://www.youtube.com/watch?v=84qaXESXdT4
https://www.youtube.com/watch?v=65weTx0haog

Amiga Afterburner (Activision port):

https://www.youtube.com/watch?v=ERJ9-i9prng

A better (but still poor) Amiga Afterburner port:

https://www.youtube.com/watch?v=l_kM65gFgng

Yeah, and also in HL civilians like scientists don't die, but sit on the floor repeating "oh god...".

Stonekeep replaced the blood spatter when hitting with the sparkle effect that usually says "hit armour, try somewhere else". Makes the game a lot harder, since you see no difference between clicks on vulnerable and armoured body parts...

Resident Evil 4, Splinter Cell on PS2. Still makes me sad thinking people played those versions.

Command & Conquer on PSX. It was okay at the time but nothing on the PC version.

Splinter Cell: Double Agent on PC. Lot's of bugs, crashes, broken light rendering, broken input during mini-games, etc.

Mafia for PS2 and Xbox. It's a worst game overall compared to the PC.

GTA IV on PC. The framerate is all over the place in this game. You can go from 60fps to 30 just by moving the mouse around. No PC can force brute it to be stable.

I've never played them myself, but

- Wolfenstein 3D on the SNES
- Pool of Radiance on the NES
- Eye of the Beholder on the GBA

look rather silly compared to the PC versions.

The NES version of Bard's Tale is also quite bad apparently, it's missing a bunch of dungeons etc in order to fit the game onto the cartridge. Thankfully though the recent remake of BTs have made all the original versions redundant.

Not a fan of NES but in my opinion it's not fair to compare NES versions with other systems because they are not ports (well, some of them are of course) but *remakes* or if you prefer *different games*.

And it could take several months presenting those *inferior NES* version for example Dragon's Lair or King's Quest.
https://www.youtube.com/watch?v=6q_9YKQtXEQ
https://www.youtube.com/watch?v=Bcv8RUWKrEg

Now I'm feeling like I'm actually a fan of NES, hmm...

I disagree with that last claim. In particular:
* There were quite a few changes made, not all of which can be reversed with Legacy Mode (notably, making BT2's Dreamspell much harder to get, making MIBL wearer in BT2 and BT3 than it was in the original versions of those games, and not allowing character transfer without beating the game first), and some people may prefer the classic version's mechanics.
* You can't save monsters at the adventurer's guild in the remaster, but you can in original BT2 and BT3. (This is probably my biggest complaint about the remaster.)
* The remaster has much higher system requirements, making it not suitable for devices which could handle the originals, like the Raspberry Pi.
* You can't transfer characters from the remake to Dragon Wars, whereas you can with the original BT1 and BT2. (Unfortunately, you can't do this with just versions available on GOG; the versions included with the 2004 game are the Apple 2gs versions (Apple 2 for BT3), while the version of Dragon Wars is the DOS version.)

Also, from what I can tell, the NES version of Bard's Tale made some significant changes, not all of which are bad; I think I may try it some day. (The soundtrack doesn't seem to be that good, unfortunately.)

I may try the NES version some day. At the moment, I'm actually re-playing the DOS version, even though I have, indeed, played the remaster.

I do need to draw a line, however; in the case of Ultima 5 NES, while it could be considered a remake, it's unfortunately so poorly done that I place it in the kusoge category, along with such gems as ET, Action 52, Big Rigs, Superman 64, Arabian Nights (PC game you can buy on GOG, not the Amiga game with that name), and Hoshi wo Miru Hito.