L.A. Noire
It's said (in some forum threads I found on Google, which I won't bother linking to) that LA Noire doesn't use the Rockstar Advanced Game Engine that powers GTA4 and Red Dead Redemption, but I'm pretty certain that this is a fractional-truth at best. You can look at any moment in the game and pick out hallmarks of Rockstar's engine - the lighting, the progressive detail and fade-in, being able to mow down lamp posts while telephone poles are indestructible - not to mention that so many of the game's mechanics are exactly the same as GTA, such that making another engine from the ground-up to achieve the same things doesn't make any sense at all. So it pisses me off when LA Noire has all the (forgive my terminology) motive and opportunity to give me the same features of a GTA, and then simply ... doesn't.
It's understandable that an LAPD officer wouldn't simply open fire in public, or get in fights with random pedestrians. On the other hand, only allowing you to pull a gun or put up your fists in extremely specific, scripted circumstances, means that the huge city with almost no secondary objectives is largely devoid of any interaction whatsoever. You can run over people with your car, but it takes some doing - Bondi seems to have broken some collision physics or AI behavior so that pedestrians will almost always bounce off your car instead of getting hit by it - and even when you do manage to jam someone between your bumper and a wall, and he dies, there's no consequence. People nearby will scream, and some might run away, but the crowd quickly returns to its business as usual; no fellow cops remark on your unbecoming conduct; there isn't even an ambulance coming to the rescue.
Crash head-first into a civilian vehicle, and you might do enough damage that both of your cars' engines set on fire -- but nobody is ever hurt. There are no seat belts, and nevertheless, you and your unfortunate victim will both be able to get out and walk around in perfect health. Clearly, LA Noire simply doesn't want you to test the safety boundaries of Los Angeles.
If you hold (rather than press) the 'Y' button by a vehicle, your partner will get in the driver seat and take you to whatever destination is marked on your map. This is a nice solution to the boredom of excessively long trips across the city. But when your partner starts driving, you go straight to a loading screen -- you don't observe the drive, you don't talk with him; it just skips straight ahead. And the conversations that you and your partner normally engage with in the car can be pretty important, often relating directly to tough questions about the case, and giving your partner the only characterization he's ever going to get. Recently I've found myself driving until my partner is done talking, then getting out and having him drive, which just seems silly.
I'm at the last crime desk of the game now, and the larger scheme behind some of the individual cases I've played is coming into the spotlight. Unfortunately, this is sometimes done with dramatically ironic cutscenes, which can be a problem in a mystery game. Now I know things about the case and the parties involved, that can't be used in interviews simply because my character doesn't know them. Even though they should be pretty easy to figure out.
Progress: Closed The Gas Man