Space Quest II: Vohaul's Revenge
When you try to "get condom" from Roger's locker on the Xenon spaceship, you get this feedback.
After the crash landing, when you try to "f**k dead body", it tells you you're a twisted mofo and that only Mark Crowe (the game's artist and co-designer) would try such a thing.
The kissing alien in Vohaul's asteroid is the alien from Ripley Scott's "Alien".
ED-201 from the RoboCop-movies can be seen in Vohaul's asteroid. He's the thing chasing you away from the escape pods - however, he has been renamed "Vohaul MarrowMatic".
While playing, type CHEAT and press return. This brings you to an alternate "THE END" screen with 255 out of 250 points.
Read the wall in Vohaul's toilet to find sentences such as "King Graham cross dresses", in reference to King's Quest. There is also a reference to Al Lowe and Ken Williams.
When Roger is caught in the hunters snare on Labion, he dreams he is Leisure Suit Larry.