Pros:

• Enough content with DLCs
• Sort of open world (with loading screens and only for Monday-Friday) for both original game and Paradise Lost DLC
• Difficulty levels could affect gameplay drastically
• Significant weapon arsenal and tools to play with - some of them are still very unique
• Has story and own approach to satire
• Visuals are somehow pleasant with its own style
• Sound design ain't that bad
• Has Gameworkshop with at least few solid mods
• A lot of secrets of different sizes and other small activities via interactions with NPCs and world
• Some achievements are fun, interesting or nod at game basics
• Has Cards

Cons:

• Periodical crashes, which in case of Postal difficulty achievements led to very annoying experience to the point that some levels just refused to download and game required more older saves (Win 7)
• Fun, but not for everyone, especially in context of "entertain yourself" gameplay
• Some minor bugs, including perma stucking in world elements
• A bit outdated and may seem quite empty compared to many open world games
• DLCs (built-in AW and separate PL) are weirder to the point that last one ended as fallout like thing
• Built-in AW isn't open world; PL has enough own issues (like NPC spawns etc).
• Some minor mechanics aren't important to the point that you probably won't use them for anything apart from achievements
• Some weapons quite a bit imbalanced (some are weak, some are no brainer)

Summary:
While I can't recommend this game for everyone, due to concept, it's among my most favorite games.
It has enough flaws on its own, but if you like it on concept level - it may bring you lots of fun or at least stuff to screw with.

P.S.

• You could go Postal here, after long hard day without issues for others
• You could buy milk and ask to sign a petition - just like in real life
• People falling and they can't get up
• It keeps your brain safe, as it all eat at your face
• Sun is shining and birds are singing, what could go wrong

Special Delivery Love Letter:
There are just games, which "yours" regardless of their downsides and people opinion and Postal 2 is one of "my games".
I played it since I launched demo on one of game magazine CDs and I still periodically play it.
This game helps me or at least just doesn't require much from me to get involved into when I'm angry, sad or sick.
I know most (if not all) of its secrets and locations probably better, than my own "neighborhood".
Sure, more experience with more games make it look more clanky, empty and outdated (even compared to 2003 game standards), but I still like it.

Pros:

• Visuals and Aestetic
• Sound
• Relaxing
• Have small additional activity
• Has story
• Wasn't expensive, when I bought it
• Relatively easy completionism with game and achievements

Cons:

• Short
• Not much to do apart from main progression and small additional activity, if you don't plan just to relax

Summary: nice game to relax and to enjoy, but quite short in terms of doing anything apart from swimming with fishes and progressing through main plot.

Pros:

• fff

Cons:

• ffff

Summary:

Pros:

• Cheap, especially during sales
• Indie, so smaller expectations
• Mansion looks nice
• Interesting theme
• Has cards

Cons:

• Even after buying it with decent discount it felt not worth it a bit (maybe if I would buy it with current discounts would worth it)
• Basically whole game is in one mansion with only one goal - to kill few people with specific tools in specific places
• Not that much to do - just driving on a plot track
• Side activities binded to achievements are minor and not that interesting
• Short
• Repetitive
• Achievements related to playtime require to play game, which has very low replayability and by this unreasonably increasing playtime for a game over more shorter, but more worthwhile games - I should just probably SAMed them
• Achievements aren't that interesting in general and more about do "this X times"
• Looks and plays outdated

Misc:

• While I don't remember any bugs, I can't fully trust my memory here, since I played it long ago, so there may be

Summary: Felt a bit like wasted time and money for me, but apart from time based achievements, I would say it's just meh and not completely bad. In any case youtube playthroughs with it looked funnier, than it actually is.