I’m not sure what’s meant by “a tricky RPG experience.” Is it one where the scenario was loaded with puzzles and “gotchas!” that require more player skill than character abilities? It is one where you later found out the GM was a horrible person, but you enjoyed the game at the time? Is it one where you generally expect the game itself to be a total train wreck and you hate the system, but the GM manages to pull off an amazing game regardless?
… I just don’t know.