8/10 coop game ever.
Not many cool coop games out there so its an absolute jem.
Pink girl levels are more action filled and dynamical but futuristic sci fi environments start to look boring over time, green girl levels have more interesting mechanics and look beautiful but more slow paced.
There a few times when we have to scratch our heads for a minute. Puzzles mostly not hard but innovative.
Bosses feel kinda same except for battle on motorbikes against spidertank it was very cool. Something is thrown at you and you have to dodge it one way or another. Sometimes boss battles give you a feeling like you are doing too much and somehow succeeding.
Final level is superb pure art you have to experience it at least once in a lifetime. Side stories are must play in what other game you get to play as a sausage or ride a snail or runaway from a dying star.
Achievments are mostly references and kinda weird. Will definitely play again.