I like games with some complexity that don't punish a player for wanting to explore other strategies beyond what the devs were thinking of. I think one of the best strategy games I've played was Final Fantasy Tactics on Playstation, as there were soooo many different ways you could play through it and it was just downright fun each time. That and it had just the right amount of challenge.

I really don't like games that are so hard or obscure that you have to look up a walkthrough just to keep going. As nice of a game as it seemed, Metroid Prime had me constantly stopping the game to see how to fight each boss and miniboss because out of your whole arsenal of like a dozen different weapons, only one of them would actually do damage, and it had to be done during a particular time of the boss fight on a particular part of the boss's body. What made it even worse was then you had a "Step 2" thing were you had to switch weapons once the thing from "Step 1" was "dead" and some new doohickey needed to be shot at with some other weapon and nothing else. PLEASE don't do that. I don't mind this little gimmick so much on very rare occasions, but this was constantly going on in this game and it's not the only culprit that has done something like this. It's fine when it's kind of obvious, like "oh, I need a fire-based weapon to kill this plant or insect creature" or "I need an explosive to blow up this armored tank." Those are fine, they're pretty obvious and they make sense. I'm talking about the "this weird obscure robot that moves all over the place like a fly on adrenaline can only be damaged by the wave gun, but you have to shoot the tiny red circle in the inner core, and the inner core only reveals itself after using mega blaster thingy that deals 2000% health damage, and it's only open for two milliseconds before it closes again. Other than that, it's totally iNvInCiBlE11!1!" I will so turn your game off and do something else.

As far as storyline complexity, I like some lore, but I like to keep playing the game as well. It's cool if you can dive more into the history or lore behind a particular place, person, group, relic, or whatever, but if you don't really want to because it's not really that important to the gameplay, that should be okay too. And it's okay if you go into detail about the main villain, but I don't need to know all the details about his college roommate's mother's boyfriend's sister and who they got married to and that they had a family heirloom of spoons that has nothing else to do with the story. Some games and stories really overdo it with some of these things sometimes and it does get to be too much to wrap my head around. XD