You can't expect every avenue to be chased down on a short form article (why does it have to be short, lack of disk space?) but WRT killer, achiever, explorer,

You can't expect every avenue to be chased down on a short form article (why does it have to be short, lack of disk space?) but WRT killer, achiever, explorer, social, some of the most powerful or memorable moments in games is a mix of them. There's a GTA series game, I think GTA:SA but maybe wrong, where there are hidden things all over the map, and you have to do crazy non-game plot urban exploring like jump your motorcycle across a river to the roof of a building where you jump a ramp to the next building and hidden up some stairs behind an AC unit there's a treasure chest or whatever. And of course there's about 100 in this game all over the entire map. So it appeals to both the achiever who's gotta get that last one and the explorer who ends up pretty much walking every sq foot of the game and every obscure corner. Pretty cool. And yes I did get addicted and eventually found all 100 and got some kind of reward. This was 10, maybe 15 years ago, and the memory of the details of even which GTA game is weak, but the memory of the experience and how much I enjoyed it is very strong. Other GTA games didn't appeal to me as much because they didn't have a reason (meaningless counters) to explore the map. Likewise there's some achiever / explorer in games like nethack. A game like Minecraft (modded, anyway) hits all four categories to some extent or another, and is quite popular.