ZX Spectrum games ported to MSX...

I don't have a complete list, but I know of these:

Manic Miner (Software Projects)
JetSet Willy 1 & 2 (Software Projects)
Chubby Gristle (G.S.E.)
Highway Encounter (Vortex)

Many games were not just ported, but rewritten for various platforms. For example here Jet Set Willy is one of those games that present on many computer systems. Here is the link to the video

https://youtu.be/hPEwl5Z9Z4k

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Most of the Spectrum games when there were ported was even left loading screen in Spectrum format,
for example Vampire is one of those games. When I tried to complete Spectrum version that was missing loading
screen, and copied MSX screen file, I was shocked because it was in Spectrum format and I didn't have to modify
it.

Another Spectrum game Way of the Tiger is direct port from Spectrum and like many of them copy screen data
every frame and modifying it to MSX screen. There is many of those games and they are very slow usually.
I think other game from same publisher is Avenger.

But other games like Future Knight (if I remeber correctly) using sprites in MSX version.
Same goes for Auf Eiedersehen Monty, that enhanced on MSX. Also they using special cheat for ZX Spectrum
and MSX and those cheat based on some systems peculiarities. If I remeber correctly you need to rename
MSX functions keys to get cheat in MSX version.

Max

Well, OK... perhaps saying "a minority" is a somehow exaggerated.
If we have a look at the number of games being sold at that time (for example, https://archive.org/details/micromania-segunda-epocha-02/pag...) we can see that the ZX Spectrum is the king, with twice as titles compared to the MSX.
So yes... MSX had its marked, but not as important to re-code the games and companies preferred to do direct ports, I agree.
As a curiosity, if you have a look at a binary dump of the "La Abadía del Crimen" game (say, the CAS file), you'll see that some pieces of the assembly code were left there, and one comment says something like "copy Spectrum screen" :D

That's very interesting about Opera Soft targeting multiple platforms at once. It makes sense, too.

I got curious about this because MSX seems like one of the only systems that got 1:1 ports of ZX games.

I'd also be curious to know where the MSX ver of Elite came in the dev cycle.

That list is from a particular shop and, although it may be indicative of the decline of MSX in that era, it does not contain all the MSX software that was available in Spain at that time.

Keep also in mind that many big hits were converted from ZX Spectrum only to be sold in Spain (Altered Beast, Power Drift, Double Dragon I and II, Shinobi, Alien Syndrome, Ghostbusters II, The Untouchables, Batman The Movie, Chase H.Q., Test Drive II, SWIV, Saint Dragon, Budokan, North & South,...). That gives you an idea of the number of MSX machines sold here: ports made only to feed the Spanish market!

Well... many weird things happened with converions, not each and every game was a 1:1 port from ZX Spectrum (fortunately or not). For instance Altered Beast is clearly a direct port but the only MSX song was vastly improved and it is much better than its Speccy counterpart:

Altered Beast in-game music Spectrum
Altered Beast in-game music MSX

Jai Alai, released in 1991 (when the 8-bit era was coming to an end and almost all -if not all- MSX commercial software made in Spain were Speccy ports) was not a ZX Spectrum port!:

Jai Alai for MSX
Jai Alai for ZX Spectrum

And remember that ports were also common between other platforms (i.e. Amiga-Atari ST).