I don’t reproduce that. It did take about ten seconds to load, but then it loaded for me in Parchment.
1893.gam
is 70MB large; it seems likely that the download was just slow for you at the time.
I’m not aware of any multimedia-enabled “HTML TADS” games that aren’t completable in Parchment.
FWIW, I’ve updated a few of the interpreters on https://www.ifwiki.org/TADS_interpreters to say “No TADS multimedia support” in the “Multimedia” column. Now, only QTads states clearly that it has multimedia support for TADS.
IFDB prefers to include a “Play Online” button wherever it can, because it is quite challenging for IF newbies to download interpreters.
First, you have to acquaint newbies with the idea of an “interpreter,” and then present them with a list of interpreters, then they have to pick a decent interpreter that works on their OS, then they have to download the interpreter, then download the game file–which can be quite challenging on mobile–and then open the game in the interpreter.
By comparison, the “Play Online” button just works when you click on it, even on mobile. QTads doesn’t even run on iOS or Android.
Currently, IFDB thinks it should include a “Play Online” button for all “TADS 2” and “TADS 3” games, but not “TADS 3 WebUI” games (which, confusingly, is a separate thing from HTML TADS 3).
Most of the top-rated TADS games in IFDB don’t use multimedia, or not in any essential way.
It’s not at all clear to me that games that do have multimedia support, like According to Cain or 1893 would be improved by removing the Play Online button.
I’m not even sure it’s wise to discourage the Play Online button for these games. “This game will play better when you download an interpreter, so here’s a list of interpreters, but, gotcha, only one of these interpreters is the good one, and good luck if you don’t even know what an interpreter is” is not going to make these IF classics more approachable for IF newbies; quite the opposite.