As a counterpoint, I found the AI of enemy creatures in Rain World to be particularly satisfying, exactly because it didn't bother trying to explain itself to the player, so you basically had to watch enemies for a while and interact with them (and die a few times) in order to try and learn how their AI worked, rather than learning specific repeating patterns like patrolling etc.
This could also make for a very frustrating experience for some players because it took time to grok the intentions and behaviours of enemies. For example, I remember a review of Rain World (on Rock Paper Shotgun) where the reviewer raged because every time he died the game respawned the enemeis at random locations, so that they were not where he had found them previously and he had to learn their new locations all over again. In truth, the game didn't "respawn" anything -the game world kept running while the player was dead, as it did when the player character was absent, much like in, say, Don't Starve and other games that take a simulation-y approach to a game world. But, to the reviewer, this somewhat complex behaviour (certainly for a game that looks like a platformer) was very unexpected and very frustrating.
This could also make for a very frustrating experience for some players because it took time to grok the intentions and behaviours of enemies. For example, I remember a review of Rain World (on Rock Paper Shotgun) where the reviewer raged because every time he died the game respawned the enemeis at random locations, so that they were not where he had found them previously and he had to learn their new locations all over again. In truth, the game didn't "respawn" anything -the game world kept running while the player was dead, as it did when the player character was absent, much like in, say, Don't Starve and other games that take a simulation-y approach to a game world. But, to the reviewer, this somewhat complex behaviour (certainly for a game that looks like a platformer) was very unexpected and very frustrating.