Wet is an action game that combines shooting and swordplay with acrobatics and gore. The main character, Rubi, carries twin pistols and a sword (she can also carry dual shotguns, submachine guns, or crossbows), and can fire while jumping, sliding on her knees, and running on walls. During these acrobatic actions, the game enters slow motion, and she will automatically aim at a second enemy, allowing the player to shoot at two enemies at once. She can also combine her attacks, such as wall running off a person or performing a sword uppercut while sliding.

When Rubi Malone, a gun-for-hire, agrees to fix a wealthy man’s problem by finding and bringing back his wayward son, she thinks the job is going to be cut and dry. She thought wrong. The job turns out to be more complicated than expected and the man who hired her isn't who he appears to be. On the run and looking for the man who betrayed her, Rubi is leaving a massive body count in her wake.