F4LL0UT: But not every game has formal combat states, does it? (as dtgreene incidentally addressed in her post)
That said, the Halo series actually combines checking the combat state with automatic checkpoints. Already the first game very accurately recognised safe situations (even during very brief pauses, better than a player ever could) and would save automatically then. There were also other factors at play like how long it's been since the last save and whatnot. It's a pretty brilliant solution that keeps the challenges real while taking the responsibility of save management off the player.
idbeholdME: I mean, in FPS, it's pretty clear. Same for RPGs. Of course there will always be exceptions and genres where this doesn't apply.
I would argue that it's not clear for FPS and FPS-like games. Perhaps there's an enemy that is physically near you, but on the other side of the wall, and the game thinks that enemy, which will never reach you, is in combat with you. Since the game doesn't have separate combat and non-combat modes, the game has to do fuzzier checks to see if the player is in combat, and the game sometimes gets those checks wrong.
In an RPG, on the other hand, it is pretty clear, provided that the RPG uses a separate screen for combat. Games like TES: Arena, on the other hand, don't have such clear distinctions; in fact, games like TES: Arena are best considered to be FPSes rather than RPGs for the purpose of this discussion!
I wouldn't trust a game to check to see if the player is in combat in games that don't have a clear combat/non-combat separation.
idbeholdME: Unless the game is built around dying, respawning, re-playing and checkpoints in general (Dark Souls, roguelikes etc.) manual saves should always be an option.
This makes me think of Syoban Action, which is built around dying and respawning, but would not be ruined by a save anywhere feature (provided the player can still choose to respawn at the last check point, as there are situations (sometimes not obvious) where, though you haven't died, the only way out is to die because there's no way to continue otherwise). Thing is, that game is all about avoiding invisible traps. With that said, with only checkpoint respawns, there is an interesting challenge in this game; the player needs to keep track of all the traps in their head in order to continue. If you forget a trap, you will die. (Essentially, the game becomes a test of the player's memory of where the traps are.)
idbeholdME: Auto adjusting difficulty is the next worst thing that could happen. I want to find a way to overcome the challenge, not have the game suddenly get easy just because it thinks I might get annoyed. I chose the difficulty at the game start, I either make it through or restart at a lower difficulty/reduce the difficulty of my OWN volition, not because the game/dev thinks it is appropriate. Just catering to casual gamers. If that feature can be turned off, no problems-do whatever you want but if you force it on me, then I would probably stop playing right there.
This makes me think of the level scaling in a few games, where being a higher level makes the enemies stronger. (Off hand, I can think of Final Fantasy 8, Wizardry 8, Oblivion, and the NES versions of Ultima 3 and 4 that do this.) I think that's a bad way to scale difficulty, and a better way would be to scale enemies based off how many major tasks have been completed (or, in FF8's case, since the game is linear just use area-based enemy scaling).
idbeholdME: If there is something urgent or the plot needs to move, you are usually prevented from backtracking
For genres where backtracking is the norm (like RPGs and Metroidvanias), I highly dislike it when a game prevents backtracking; instead of changing the game to fit the urgent plot, the plot should be changed to allow for backtracking.
