I have been interested in a game called Star Breach and the other free titles available from indie publisher Slow Death Games. I love their game Wild in the Streets (punk gang warfare), and have been interested Star Breach (a mini-agnostic sci-fi skirmish game) ever since its successful kickstarter in 2019. I haven't played it yet, but I'm impressed by it's easy and accessible ruleset.
For all of my decades as a tabletop miniatures and roleplaying gamer, I have never been interested in superhero games (truth be told, I've never been all that interested in superheroes).
But now, the designer of Star Breach, Elijah Kellogg, has released a free set of rules for Supers, a superhero skirmish game built on the Star Breach rules.
You can download a free PDF of the Star Breach rules here and the Supers rules here.