Your thoughts on adding a playtest pop-up with options?

[Norbert]

[...], namely a command-line option that specifies where the DAT files are (which, for apoplexy would then be e.g. "DAT=../prince" or something similar)?

AFAIK, MININIM already implements this.

I don't think it does.
I will have apoplexy copy LEVELS.DAT from prince/ to MININIM/ just before it launches MININIM.
This should work as a workaround.

[Norbert]

I have finished this work.
I'll release apoplexy 3.3 this weekend.
[Edit: Done.]

[Norbert]

So, yeah, if SDLPoP or MININIM ever add any new legacy tiles, let me know and I'll add them to apoplexy's native tiles screen.
I don't really know what might currently be missing, especially for MININIM.

Of course, I'll also need a GNU/Linux and Windows version of the actual native implementation.
To put these up at popot.org, so apoplexy users can instruct the program to download these for use with playtesting.
For SDLPoP, I can manually compile the GNU/Linux version myself. For MININIM I cannot.