Pros:

Large non-linear maps
Clever level design
Detailed and variable areas
Loads of blind aleys adding to the sense of 
Mood shifting with each new area
Great feel for the various faces of Japan (from tight urban spaces to rural and mountain areas)

Cons:

Some minor bugs (got stuck for a while in one location, but only once)

Conclusion:

A relaxing campaign with amazing level design, epic maps and a great eye for Japan (without the usual in your face quote-spotting typical for fan depictions of Japan). Not the hardest campaign to play but definitely one of the best in terms of originality and variety of areas. Great fun.

Pros:

- long and cleverly concieved maps
- variable environments
- great atmosphere and suspense
- clever usage of players expectations regarding typical L4D-things like safehouses
- cruel, but entertaining surprises

Cons:

- no loading bar when turning the wheel
- no direction marker after the APC arrieves in the finale

Conclusion:

Even though the map lacks dialogue or scripted money shots sequences it delivers great action and suspense in cleverly conceived maps. The constant switching of different environments within levels keeps the campaign interesting and fresh.

Pros:

- long playtime and vast levels
- good voice acting
- loads of cleverly constructed events
- tons of jokes, references and neat details in the environment
-  imaginative level design

Cons:

- often the monologue can’t be heard because of the higher volume of zombie shrieks which can cause confusion
- in some places specials get stuck because of some environment glitch

Conclusion:

This campaign provides many hours of fun and challenging gameplay. Thanks to the voice acting, the epic proportion of the chapters and the playful attention to detail it even overshadows some of the official campaigns.

Pros:

- great atmosphere
- clever and stunning leveldesign
- an upgrade to regular gameplay (gas canisters as currency)

Cons:

none

Conclusion:

Feels like a blend of L4D and Portal, where the survivors find themselves in an intensely paranoid environment and the “director” turns into a GLaDOS-like personality with a cruel sense of humor. Questionable Ethics is one of the most original and clever custom maps and does provide not just hours of fun but also wonder.