Boy, it's always funny for me to hear that The Supreme Element was way too easy for people; when I originally made it, I thought it was fairly challenging, but my beta testers all told me they were overleveled for the later bits. So I literally just ramped up the numbers for the later fights, thinking I may be overdoing it a bit, and still I hear from a lot of people that they had no difficulty at all. I suppose it's because I knew where everything was, so I never had to walk in circles and re-fight the same enemies as a result.
Well, I did write another text-based game for MTJ called "A New Project", which is more puzzle-based and doesn't have a combat engine, but focuses on Zork-style puzzle solving. And way back in the day I wrote more of a proof-of-concept game called "Depths of the Tickle Torture Chamber", which was sent out over the old email based "Morandlias' Ticklers Journal" which was fairly primitive by Supreme Element standards. This is the only game I know of which uses this combat engine, though, because I specifically wrote it from scratch with the Inform language. If there are any Inform programmers out there, I'd be happy to share my code if needed.