Hi. Yes and well searching a bit on the web i found there is another game with a merman even if far more of classical mythology look and less cool modern guy style since well it's Poseidon he seems to play a major role in a city building game call Poseidon : Master of Atlantis. Well that and I guess since they are little mermaid games for little girls they probably are scenes in them with Ariel's father but sure the count in merman videogames characters is a bit short that being said a lot of ocean fantasy themed video games has pirates guys as heroes that may be the closest you can go besides these few examples well that being said i'm sure they are more.

For more personalization they're mermen and mermaid in The Sims 3 and 4. And well some Water Pokémon could look more or less mer like and they have male and females/were not gendered in the first game that said maybe nobody else but me feel Aquali looks like a mermaid fantasy animal. That's all the mermaid guys in video games i can think about without going on deep research but i think they maybe a few more probably. They are a lot of video games after all most not all that well known so everything possible beside maybe with RPG maker or something someone in this very community somewhere had made a mermaid themed unofficial game for the mermaiding community who knows?