Following his humorous adventures in previous game, Roger Wilco is relaxing at his favorite pub somewhere in time and space when heavily armed soldiers enter the room. Carrying a parting message from Roger's old nemesis, Sludge Vohaul, they plan to get rid of the janitorial hero, execution style. That is, until a man with an over-sized hair dryer helps Roger escape through a time rip into the future. Now Roger Wilco has woken up on his home planet, some time in a meta-fictional Space Quest XII. It is a grim, dystopian future: the series has gone to ruin without its hero, and Vohaul rules supreme. Roger must find a way to avoid Vohaul's henchmen, fulfill his destiny, and learn about a few surprises that await him in his own future.
Space Quest IV is the first in the Space Quest series to feature Sierra's icon-based SCI interface and 256-color graphics. The command set includes icons for walking, looking, using or taking, talking, smelling, tasting, as well as inventory access. Roger Wilco is shown on the screen from the exterior in multiple viewpoints. Like in the previous games, inventory-based puzzle-solving co-exists with timed tasks and various hazards that will kill Roger if the player is not careful.