I just finished the game with 4 of 8 achievements.
Now I know what the plastic soldiers are for.
+) The story is fun and the setting with the agents starting on top and on bottom was excellent.
+) The backgrounds were even better than in Visitor 1 I think. Also lots of animations.
+) The sound effects were very fitting
+) The puzzles - logical and fun.
+) The pacing. There were what feels like millions of different, well drawn rooms, that where unlocked one by one without being overwhelming. Also the idea of using shortcuts was nice.
+) Switching between player characters
...and playing the green slime
+) It was generally fun to play, made me laugh out loud several times.
-) The puzzle with the car. This almost ruined the beginning for me. Even after I got the solution I think this is badly implemented. Just walking away should have been a solution.
-) There could have been more interaction between the player characters
I really thought I could use the barrel to exchange items. I often thought "as soon as I can exchange items, I'll give that to the other player". On the other hand it was fun to see items in the range of one character that the other might need (valve, condom,...)
-) The dialogs were a bit strange, often I could not figure out following which pattern the options appeared and disappeared.
-) Two glitches
*) after lifting the crane, the magnet was still visible from the screen with the squirrel
*) after Scar was cought I could see him standing on the roof from the distance.
Great game, I really enjoyed the story, characters, backgrounds and puzzles. I think chances look good for the upcoming awards!