Instructions
Start a new Act to receive a video briefing about the mission. The briefing video plays automatically when the Act begins.
Look for the character you need to shock. The character is the person who talks to you during the briefing. In Act 1, the character is Hal Emmerich. In Act 2, it is Sunny. In Act 3, you need to find Naomi Hunter, and in Act 4, look for Colonel Campbell. The person may walk around or sit down while he or she gives you the briefing.
Use the left analog stick to back up the Mk. II robot so that you distance yourself from the character. Press forward on the left analog stick to make the Mk. II robot move at high speed.
Ram into the character's legs to shock and startle him. If done correctly, the character comments about your actions or scolds you.
Wait until the end of the briefing video to receive the unlocked face paint.