Can I play Deltarune without a Windows or Mac PC?

What platform will you play on?

As a GNU/Linux shill, I will describe the steps to get Deltarune running.

First, install WineHQ (allows Windows executables to run on Linux). Then, download the MicrosoftⓇ Windows™ copy from the game vendor's official website.

Alternatively, you could just use a good 'ol VM or just dualboot (like I do).