Hey, nice job there. This is further than I've gotten in making mods, and that's not even making a game from scratch, lol!
There's a game-breaking bug, pretty early on, though. As soon as I enter Castle Blackflag, I can't move. I can make Kieran change the direction he's facing, and I can read the sign next to him and open the menus so all of the controls seem to be working fine. Maybe you accidentally placed an object on the spawn point so Kieran is getting stuck in it? I don't know what could cause this, and I'm not exactly a programmer, but I can at least bring it to your attention.