The Secret of Monkey Island is a point-and-click adventure game originally developed by Lucasfilm Games / LucasArt for the PC. It was also released for Amiga, Sega Mega CD, Atari ST, FM Towns, Atari ST and classic Mac. This video shows a fan-made port to the C64.

You can get the C64 version here:

https://csdb.dk/release/?id=237672

Guybrush Threepwood is a young guy who wants to become a pirate. On the way following his dream he ends up on Melee Island, deep in the Carrebean. The Very Important Pirates, de facto leader of the local pirates, give him three trials to pass to become pirate. But Guybrush's troubles do not end there. He soon comes across the beautiful Gouvernor Marley and the evil ghost pirate LeChuck who is terrorizing the island...