Gloomhaven is more game than puzzle. Some tabletop super-optimizers (who played at intentionally elevated difficulties) liken it to a puzzle, but I never felt that way while playing it. (And I am one who *hates* puzzles in my games.) Gloomhaven did have a couple "puzzle" elements in the meta-plot for unlocking some stuff, but we just looked that up. Not a clue how or if the digital adaptation will be handling that.
Note, however, the tabletop game's expansion, Forgotten Circles, is near-universally panned for being terrible scenarios, most of which are puzzles (and most of which don't give proper feedback or guidance toward solution even for those who like puzzles.) I don't believe this includes or is currently set to include the Forgotten Circles content, though.
To answer the question:
* Games have good, meaningful choices and you can get to the result (winning the scenario) in a wide variety of ways with creativity.
* Puzzles are rather constrained in your routes from start to finish and there tends to be a "perfect choice" at any junction.