This is widely considered the gold standard of fan games. It follows Clover, the seventh human to fall into the Underground. : The Justice Soul (Yellow). Features : New areas like the Dunes and Steamworks.
Here are the gold-standard fan games that best fit the "Extra Quality" label. undertale fan games unblocked extra quality
Underswap is a popular "role-swap" AU (Alternate Universe), but Team Switched took it to another level. This fan game features fully redrawn sprites, swapped roles (Papyrus is now the lazy skeleton, Sans is the eager one), and remixed music. This is widely considered the gold standard of fan games