I'm like the boss from the end of the Nintendo game
Nintendo games usually end with the player having to defeat a boss. Defeating the boss is extremely difficult. Bronson is that boss.
Bronson might also be using the Nintendo game as a reference to the rap game, implying he is his own boss. .
To help improve the meaning of these lyrics, visit “Elimination Chamber” by Domo Genesis & Alchemist (Ft. Action Bronson, Earl Sweatshirt & Vince Staples) Lyrics and leave a comment on the lyrics box