The Entropy Centre is a largely Portal-inspired game that will require you to plan out what you’re doing even more than Portal. (Note: there are a few chase sequences and a few battle ones that break this pattern.) And there’s a cute robot called E, and your portal-gun-equivalent has an AI too. Basically, it’s Portal but the AIs are friendly.

And then there’s The Talos Principle series, which is even more like what you’re looking for.