I could have sworn I made this a feedback before, but I suppose it wasn't a dedicated point. I figured since today is my birthday I'd address a point I like in games as a feedback post for HN2...why? I don't know.
Anyways, I think a way to boost reviews on HN2 is the possible randomization of the game's puzzles. I'm sure players know that with a guide online or on repeated playthroughs how to speedrun the puzzles and codes in the game, cutting the playtime down dramatically. I mean Otto's section can be skipped over by just using a shovel on the safe and putting in the code. I can get however that some players might get bored with the whole 'man I actually have to solve the same puzzles just to get a different code?' so I suggest a possible tweak to keep everyone interested.
Randomized puzzles. Not just randomized codes, I mean different types of puzzles. Now this might be something big, like needing its own update but I would have my own personal enjoyment go through the roof if it happened. I imagine things like the jail cell and safe would have to just only have randomized codes but imagine if like in one playthrough in order to gain access to the upstairs of the crime scene you'd have to assemble a ladder outside instead of being able to immediately use the scissors to cut the police tape blocking the stairs. Or imagine the officer keeping a key needed for the basement on him seemingly at all times so in order to get it you'd have to wait until he either puts it down on a table or drops it into a safe. Requiring the player to either wait until he opens the safe then distract him or use a camera to watch him put in the code, giving use to the cameras.
I'd type more examples like for Gerda or Otto but I don't have Nitro so i'll have to extend it out in the comments.