These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Critical Dissonance: The game was widely praised at the time of its release, but the general consensus today amongst the general gaming public seems to be that in hindsight it actually had significant flaws, especially in comparison to Far Cry 3 and other open-world shooters like Fallout3 and S.T.A.L.K.E.R.. However, a number of industry insiders cite the game and many elements of its interface and design as inspirational and a major influence on their own work.
Demonic Spiders: Mortar operators in Act 2. Also, the soldiers. They soak up ammo, do a huge amount of damage, and have the tendency to try and run you down with their cars, an instant One-Hit Kill.
It's rather amusing watching a bison walk head-first into an open car door and spontaneously drop dead.
If you crouch into a shallow part of a lake and slowly lose health, using the Heal Thyself button produces amusing results, such as your character setting a broken arm in three places to pulling rebar out of his torso. Observe!
Older Than They Think: The "revolutionary" Wide Open Sandbox gameworld of Far Cry 2 was actually done a couple years earlier in Boiling Point: Road to Hell, a revolutionary game done in by a buggy pre-patch release and its non-big-name publisher/developer and their lack of publicity. There's also S.T.A.L.K.E.R.: Shadow of Chernobyl.
Porting Disaster: The PC version started out locked to the same "fake" widescreen mode as the console versions (ie, cutting the top and bottom off a 4:3 image to make a 16:10 image instead of extending the field of view left and right). This was eventually patched due to complaints that players with multiple monitors were dealing with a field of view so vertically compressed they couldn't see anything.
Scrappy Mechanic: The Malaria mechanic forces the player to occasionally undertake a Fetch Quest to get pills. Also, the respawning checkpoints.
Squick: Some of the ways you perform an emergency heal on yourself can be pretty gross, like pulling a bullet out of your palm with pliers, or pushing a bullet out the other side of your arm, or resetting your arm with a loud cracking noise.