Trespasser, a dark fantasy tactics RPG
Fine, I'll talk about an OSR game
Touchstones: D&D 4e and 2e
Genre: OSR, Tactics game
What is this game?: Trespasser is a game mixing together 4e style tactical gameplay with OSR dungeon crawling and character creation
How's the gameplay?: Trespasser is a game heavily influenced by 4e and OSR, characters are built by running through a level 0 dungeon with a bunch of characters and picking out whoever survives at the end as your 1st level character, character creation as such involves going through a tutorial dungeon with around 10 or so peasants characters, who will be brutally murdered in various fun ways, you then pick a class (what you expect) and a theme, themes give your character generic skills like "Do a punch" or "Cast a firebolt". Character creation aside, the gameplay is a fairly standard tactics game, if you're familiar with 4e or Lancer you'll probably get to understanding the combat pretty quickly, the main thing is that while most tactics game focus on isolated skirmishes, Trespasser tends to focus more on attrition-based dungeon crawling, in Lancer you probably won't get blindsided by a boulder trap nearly squishing you, but in Trespasser you might.
What's the setting (If any) like?:
In all seriousness: While the setting obviously exists, Trespasser's strength is more in its core gameplay than setting, because the setting is honestly a pretty bogstandard dark fantasy, the main interesting thing being that the average game will have a pre-made villain already in the form of the Lords that the players must take down. I believe this genericness to be a strength, though, as players can remold the setting into whatever they want!
What's the tone?: Well, its in the name, DARK fantasy, shit sucks, and you're trying your best to make it better, but it's an uphill battle
Session length: 3-4 hours sounds reasonable, dungeon crawling is pretty quick but combat is still decently slow
Number of Players: 4 players is a minimum, I'd cap it off at 6
Malleability: As said above, Trespasser's setting is really really malleable, if you're fine with the darkness baked into the very mechanics, you could probably make any setting work
Resources: Random level 0 character generator and online character sheets are available
Trespasser is not my favorite tactics game, but its still a great time, If you're into OSR but want something with more "spicy" combat, definitely check this one out