It'd be like porting from HL1 to HL2, alot of recoding. HL1 to project Black Mesa would be more of an equivalent.
And on the other argument Marcem, its not like he'd get rid of this blockland, he would just be working on it as a side project. He also knows the system and would just have to change sintax and recode things hes already coded. It would just be more tedious then challenging, which might be a bad thing. Also, he would just keep the old models.
Thinking of Blockland 2 just made me excited for some reason.