As someone who is reviewing FMs. Old terrible stinkers are fun to review only if they contain something unique or strange to make fun of. Or are terrible in ways that allow me to tear into the author guilt free. But most bad missions are not like that. Every FM from Koobze, to Ominous bequest, has genuine effort and work put into it, and without a mission being bad enough to truly mock, all I am left with is the nagging feeling that I am bullying someone who might not even have been an adult when the mission was made. I am also reminded constantly of the idea that every FM is a miracle regardless of quality (though certain FMs such as Koobze do challenge that assertion)

The Gambling man is the worst case scenario for me. I don't want to hate this mission. Plenty of genuine effort was clearly put in, but it's clear that there are plenty of problems which really should have never made it into the final build. As well as the bad literacy skills (which could just be from not being a native speaker) there are staircases which are not smooth to climb, misaligned textures, the missions title doesn't appear in game... yet none of it's issues quite push the mission into actually not being fun.
(Ok, there is one death-trap which will randomly kill you for examining some stairs. That's just cheap, it's also a one-off, so I won't hold it too heavily against the mission.)

The mission does have some OK brushwork in places, and in the latter half, is actually pretty OK in general terms, but even at it's best, it's a boring house mission with little to distinguish it from any other house.

Unfortunately, even trying to be as charitable as possible, I am still forced to conclude that the mission, with all it's obvious flaws, simply isn't very good. It's not awful to play, and you can certainly have an OK time playing through it, but it's not a good use of your time.