Anyone new to IF will probably have trouble with any of the file types. Some are just more common than others.
Even those authors who did write INSTALL INSTRUCTIONS may not get their message through in the competition, because if you click on a submission, you can get the file without seeing the install instructions, because you have to click at "view game page" in order to see install instructions.
So itch.io isn't making it easier.
Except for VERY few examples on the internet, ".blorb" is always an ADRIFT 5 game and can be handled by any Adrift 5 interpreter, whereas ".gblorb" requires an glulxe interpreter with blorb support (I don't know if all glulxe interpreters has blorb support) and a ".zblorb" requires a z-machine interpreter with blorb-support.
Finally, "Murder Most Foul" is distributed as a taf-file which both Adrift 4 and 5 games can have as an extension but in this case it is also an Adrift 5 game so that also requires either Frankendrift (Mac, Win, Linux), Adrift Runner (Windows) or Fabularium (Android).
