The Sailor And The Siren is a two-player, card-based rpg about exactly what it says in the title.
It's 11 pages, with solid layout and colorful ocean backgrounds that start above water, and then sink into the depths.
You play by playing cards of different suits to indicate how your character (the siren or the sailor) is regarding the other. Higher numbered cards take effect first, and specific cards played during specific parts of the game trigger additional narrative effects.
The Siren starts with a larger pool of cards, and has pretty strong narrative control throughout, so there are definite themes of uneven power dynamics alongside the themes of romance and predation.
Overall, if you like two-player games that are intense, and optionally either dark or romantic, you should pick up The Siren And The Sailor. If that's not quite your cup of tea but you still like the structure, S&S *is* mod-able, but you'll want to read it through once first to figure out where you want the storyline to diverge.