perhaps someone can help developing a kind of code converter (to assembly, C, Boriel’s ZX-Basic Compiler, etc.) or a cross-compiler - since the idea and the need is there, i can’t see why this can be so impossible! 
(my laziness blocked me to understand better how the ZX-Spectrum version of arcade game designer works, i wer mostly focused on cross-compiling since years)
Hi Jonathan, nice to see a post by you in these forums!!!
There are at least two other game engines currently being developed for the MSX from what I can read in the forums in other threads, but the AGD is immensely popular in the ZX scene, and thus, porting it to MSX would be a huge draw to bring developers to MSX! My hands are currently full with 3 game projects, but if anyone is interested in a community effort, some some shared code repository where people can start contributing to make this port, I'd be happy to collaborate 
Thanks Journey. It's always great to see a game I've written getting a good write-up in Retro Gamer or elsewhere. It's especially pleasing to be able to help others see their own games appear in print, which is the point of AGD.
Version 0.7.3 was released a few days ago and can be downloaded from here. There's a simple demonstration game included, plus the latest version will import many of the 150-odd Spectrum AGD games as tape or snapshot files, generating placeholder graphics for the other supported machines. As usual, source code for the Z80 engines and compilers is included in the downloads but if you like Santiontanon's suggestion of a community effort to get an MSX conversion going I can set up a project on a shared code repository. As I said before, the Timex graphics mode is pretty much identical to the MSX so would be the ideal compiler/engine on which to base the MSX version.
We have an Enterprise version underway now and I'm liaising with the developer to get MPAGD's palette editor working properly with the machine.