[thethirdone]

> In Opus Magnum, I finished every puzzle on my first try.

I never was close to failing to finish a puzzle in OM. It was just a matter of how poor my solution performed whatever metric I chose to optimize first. The puzzles at the end of the campaign had me "give up" and settle for an ugly slow solution though.

> I feel no compulsion to return to OM after finishing the main campaign

If you haven't tried the Journal puzzles in OM, I would recommend you give them a shot. Many of them are in confined spaces rather than an infinite plane. I have yet to find a puzzle as hard as the ones in the TIS-NET directory, but they are a step up from the rest of the OM puzzles in terms of difficulty.