Who owns the rights to One must fall 2097? and is it freeware?

in 1994 epic mega games published a game made by diversions entertainment called one must fall 2097

in 1999 diversions entertainment made it freeware and put a download link on their website

i am currently in a bit of a argument with a reddit mod who appears to think that despite diversions entertainment putting on their website that they are making it freeware along with a direct download link is not enough evidence to say that the developer had the right to do so

Epic doesn’t claim on-going ownership rights to One Must Fall 2097. We accept the owners giving it away as freeware.

I confirmed with the owners of the IP that users “users are invited to modify and distribute as they please, as long as they do not charge for it.”