Here's some information on it. https://gekk.info/articles/towns-tour.html

EDIT: Here are some of the highlights:

• Towns OS had a custom GUI that was fairly advanced for the time.

• Towns OS included multimedia support.

• Towns OS had an API that provided advanced sound and graphics capabilities.

• Towns OS included support for overlaying videos in different modes, which boosted gaming and multimedia support.

• The FM Towns computers came standard with a mouse and gamepad in an era when PCs typically didn't have these things.