I’ll second that bit. Most people who want to do more complex things in Twine use SugarCube because it’s a lot more flexible and has a lot more built-in features.
Also, I have my Universal Inventory System (UInv) written for Twine/SugarCube, so combining your combat system with UInv would get people a lot closer to easily making Twine-based RPGs.
As far as the number of people who play Twine games goes, I don’t know, so I’d merely be speculating on that. However, I can tell you that the number of people developing games in Twine has been steadily rising. Looking at the statistics of the r/twinegames subreddit (where I’m a mod), it hit 1k subscribers in Aug. 2017, 2k subscribers June 2019, and is on track to hit 3k subscribers in about two months (source). Or, to put it another way, it took just under 2 years to go from 1k to 2k subscribers, and it’s likely to take under 1 year to go from 2k to 3k subscribers. It’s a promising trend.
I’d be surprised if this didn’t also translate to more people playing Twine games as well.
Furthermore, I see a lot of Twine/SugarCube developers asking for help with a combat system. The more tools we put out there, the more popular the format gets, and the more Twine games there are out there for people to play.
So, thank you for the combat system, Thierry, it’s likely to be a popular Twine tool, though probably likely to be more popular if you port it to use SugarCube as well.
Let me know if you need any help with that.