I have thought about a sequel, but I figured out that I would need a stronger game engine than PuzzleScript (what this game uses) to create what I envision for the sequel. PuzzleScript does not allow for information to be transmitted between different "levels," which is why Remnant Labs actually uses a single huge level; my plans for the sequel would be more complex and lag would become a big issue, so until I learn how to use another game engine – and probably get a more powerful computer – I don't have plans to make a sequel.
However, I will probably make a different game of a similar style to Remnant Labs at some point, especially seeing how popular it has become, I just need to think up the right mechanics.