I figure it's not a problem with porting the game, but them putting more time and effort into the porting. We know some of the changes they were making were going further than just a port-job. Maybe they realized it had so little in common with the PS2 game, that they might as well continue onward and not be bound to Rygar: The Legendary Adventure.
I'm sad to see it slip again, but if it leads to a better Rygar game I am all for it.
"I feel like I could take on the whole Empire myself."