I am actually also open for names, I don't know exactly what this thing is.
As for names, maybe something cute like ClojRPG?
For example side effects are just vectors of `[:tx/foo param]`.
But I highly recommend changing the capitalization of Maker to maker to avoid being mixed up with the product RPG Maker. Adding "an" helps signal that it's a descriptor instead of a name too.
Core: An RPG maker and engine for Clojure.
CrystalCore - because RPGs must have some sort of magic crystal, it's the law
CreataCore - why limit the name to RPG theme in case it develops into something larger?
Just a few quick name suggestions for OP.