As far as I remember, no one continued Lab Rats. They made a new version of Lab Rats, with new renders and code, changed a number of things, added new content, and dropped some content. I think they even changed game platform too. I'm fine with that. It's what I call be inspired of another game. But what Allm is planing to do, as far as I understand, is to take the code and renders that the original dev has made and continue from that point. That is stealing, and it will be a Frankenstein game, as he will not be able to continue the game in the same style as the original dev did.Beside that. As far as I understand. He is not planning to finish the game. He will just make a half ass finish for a few paths, he likes to be finished.
This is also one of my favorite games, and I would hate to see it becoming a Frankenstein. It can't be continued without the original dev. His style is too unique for that, and his style is why it's so good.