If you want to earn Companion Barrel achievement or trophy in Duke Nukem Forever, you will need to unlock the secret closet at the end of the Forkstop.
First you need to find the barrel with red heart on it, then you need to place it over another heart just outside the closet to unlock it. When the secret closet opens, you will earn the achievement or trophy.
Companion Barrel Location – Unlock Secret Closet
Note. If you are facing performance or graphics issues with the game, don’t forget to check our Duke Nukem Forever Troubleshooting Guide.