A Predator Space Travel game where you go to various randomly generated worlds and just hunt the indigenous creatures there. You'd have a Predator species wide leaderboard of sorts where the most experienced and renowned hunters with the most quality kills and highest personal honour are the cream of the crop, and you want to hunt your way to the number 1 spot.
Going to savage worlds and hunting huge beasts would be quite prestigious, provided you don't use any advanced weaponry. Game preserves like in the movie Predators would exist, less prestige due to the Predators having the turf advantage, but it's good practice on the various random persistent species throughout the galaxy.
Hunting sentient species gets real interesting. Hunting non-combatants, pregnant individuals, children, old aliens, all of that is dishonourable. Therefore, the only sentient beings worth hunting would be those in soldier/combatant roles. The AI of these sapient soldiers would be their main advantage, for every one you kill, the ones after would learn more about you, and how to counter your hunting tactics, something that even the largest and most powerful beasts of other worlds would not be able to do. Given enough time on a certain world, the locals would eventually manage to create Anti-Predator tactics and weapons, and therefore pose the greatest threat to you.
Break the rules of the hunt, and you lose honour and prestige. Do this enough, and you'll be branded a criminal of Predator civilisation, which means that other Predators will be sent to put you down. This would be the greatest challenge of the game, once every other species you've hunted becomes too predictable or too easy, you'd have to deal with hunters of your exact caliber, outnumbering you.