How often do you play through games that you like? Do you think you need to play through various games, multiple times to get a proper grasp of their systems?
Depends on the game, depends on you.
Some games have a lot more up-front complexity. Some games have a lot of subtle details. Some games have a lot more mechanical processes to master. Determining which is which requires good judgment. Determining if you really understand it takes good judgment.
I don’t have very consistent records of how many times I’ve played through all the games I’ve played. I’ve beaten Demon’s Souls twice, Dark Souls 1 at least 7-9 times. Dark Souls 2 maybe 3-4 times. Dark Souls 3 once. I’ve beaten God Hand once, same for Bayo and Ninja Gaiden, so I haven’t played hard mode in any of these games unless it was unlocked from the start, which I know I should do, but I just haven’t had the time. I’ve beaten Mirror’s Edge maybe 15-20 times. I’ve beaten Tales of Symphonia twice or 3 times. I’ve beaten DMC3 twice. DMC4 maybe 4 times on various difficulties. Mark of the Ninja perhaps 5-6 times. DXHR perhaps 4-5 times. MGR at least 7 times. Beaten HL2 perhaps twice, HL1 once, maybe twice. Halo 1 twice, Halo 2 once. Hotline Miami at least 4 times. Crysis Warhead at least 5-6 times. Beat Dishonored at least 6-7 times. Beat Wind Waker 3 times. Beat Cave Story twice. In both Thief and Thief 2 I stopped on the last level. Super Mario Bros I beat 6 times in the same month.
I replay it if I have time, if I like it, if I feel like there’s more content, if it’s been a long time since the first time I played it, if I happen to look at it when I have time open.
I think that replaying games is ideal, I don’t always have the time for it. I think I got the gist of a lot of the games above on my first playthrough and very few of them had me actually significantly learn more across playthroughs. I also supplement my play with gleaning facts online, seeing speedruns, reading about tricks and techniques, etc. I try to limit it sometimes so I figure things out myself, it varies. If it’s a crazy action game, I tend to look up whatever advanced techniques there are. Sometimes I wait until I’ve played the game a bit before doing that. Sometimes I find games to play because I’ve seen advanced techniques from them and think it’s cool.
Replay if you can and if you feel the game deserves it.