Back when DELUXE was just a recode with graphical improvements there was a planned secret boss that you'd be able to fight after finishing the game.

After going on the old wiki and finding the Anticheat page, you were supposed to type the Konami code in the titlescreen to unlock "ONE LAST CHALLENGE".

The challenge itself was supposed to be the hardest level in the game, akin to Mario Galaxy 2's secret challenge level. After beating the challenge you would enter an arena location of sorts where you'd fight Anticheat. A church-like location comprised of the wooden log platform sprite was also considered.

Big gimmicks of his fight is that he was able to manipulate every single in-game object and change the physics values. Eventually, after damaging him enough, he would appear behind the game window and begin moving it on his own while the fight took place.

After beating him, you'd be prompted to a cutscene where he would berate you, closing the game. This would have unlocked the final achievement of the game.

No progress was made on this. Anticheat's design was never finalized.