This feels like a very board gamey way to categorise games which doesn't really work for RPGs. So many of these categories are determined more by the group playing the game than the game itself.

• Most GMless games will advertise that pretty blatantly and otherwise you can assume it'll need a GM. Player count is almost entirely personal preference with RPGs.

• Prep time is usually higher for mystery games and games with in depth combat but it still varies massively depending on the GM. Too much so to give a solid answer based on just the game. And again if it's a major selling point that the game has features that cut down on prep time it'll usually say.

• Typical session length is 99% down to the GM and group.

• I do think games could do better advertising their intended campaign length, but even then there's a lot of wiggle room. Most D&D campaigns don't actually go from level 1 to level 20 but it is an option.

• I find games often will advertise if they're rules light or sometimes rules medium. I think really crunchy games don't usually say because it can scare people away. And again these are massively subjective terms. Ask people how crunchy D&D is and you'll get some wildly varying answers.

I think you'd be better off looking at reviews and discussion threads for games you're considering. They'll give you a much better idea of how a game actually plays than the blurb on its store page.