Yeah this game is moddable, mostly in the sense that you can extend/replace dialogue. Create new scenes, new characters, new weapons, and attacks. However, since you don't have access to the game code, you can't add new mechanics (yet..., I'm looking into seeing if you can decompile the swf file, add new/extend code and then recompile it).
I am currently working on one such mod, but it's far from releasable. Basically I'm extending the available options for all the encounters/npcs available. Simply working on them one at a time. I began by simply making grammar changes that I felt made more logical sense, then a friend asked me to add a kink of his to a sex scene and it grew from there.
Currently the character I am working on is the ever adorable Subni, and once I'm done with her I may look into releasing it here as a proof of concept mod as I move onto more NPCs/encounters.