Opus Magnum is one of the most polished Zachtronics games IMO. The presentation is great.
Exapunks can be pretty tricky with the distributed nature, which share some similarities with TIS-100. Like Opus Magnum, though, there are no restrictive code size limits, meaning that some puzzles can be solved with brute force masses of code. It's not as bad as Shenzhen I/O where you have to deal both with a tiny MCU and routing.