Cruelty Squad is also a successful FPS title built with Godot, but its deliberately hideous aesthetic probably makes it the worst possible way to sell anyone on the merits of the engine.
I unironically love cruelty squads aesthetic, its one of my favorite indie games in recent years. Even the store description calls it a "sewage infused garbage world"- and it is, but its also oddly charming, and perfectly suits the game's theme and atmosphere. Though its probably not very enjoyable for those with epilepsy
I've heard its style described as the product of someone understanding good design but doing the exact opposite of that out of spite, which seems pretty fitting.
https://www.youtube.com/watch?v=Atb3yFNazmU
https://www.youtube.com/watch?v=SFIOmb1hseA