At the start of the pandemic I got back into D&D, correctly surmising that I and my friends would benefit from something to do online together during lockdown.
Character death is often held up as a positive feature of OSR games, sometimes associated with a degree of machismo and the idea that without the possibility there's no challenge or interest. I don't believe this - video games manage to have challenge with no real possibility of failure, you try again until you get it right. Stories where you know the hero is going to survive can still be tense and interesting. There are other stakes.
The system I'm using for my current game is based on the Black Hack, and perhaps my favourite part of it has been the experience system. In place of XP certain actions count as 'experiences' and are recorded on the character sheet. Players can check off a certain number of them to gain a level (in BH equal to their current level, though I'd suggest equal to the level you're trying to reach.)
Mermaids are hypersocial carnivores. They feed exclusively on land-dwelling mammals, including humans and demihumans.