Never mind! Two hours after posting this thread I actually found it on my own!
Appears the name wasn't Monster but Beast, and it even has it's own
Wikipedia page. There are a couple of modernized remakes as well, but the original game is available from
here. Looks like it's definitely not sold or supported by anyone and it's even unknown who owns the rights to it anymore, so I'd say it is safe to consider it abandonware.
Edit: Upon running it it appears it was in fact freeware/shareware originally. Also seems like some of the things I thought I remembered about it was wrong. Anyway, experiencing nostalgic gaming bliss right now.