78 puzzles in & they've definitely started to take more time. I average about 4-6ish minutes now filling them out because of how big they've gotten. I wouldn't say they're difficult, just more on the time consuming side, though I still think they're the right level of difficulty since I might have to redo some squares, but never comes off as frustrating (maybe slight annoyance, but that's it). While I do think the game could benefit from being a bit harder (as mentioned above), it's pretty much the right amount of hard, especially when I just wanna pick it up & play a puzzle between college homework.
Also the fact that every single puzzle is available from the start is a mixed bag. On the one hand, some people probably like this since they don't feel as though they have to stick with doing the easier stuff. But on the other hand, kind of feels as though the game is just like "here, it's everything I have" and you can just skip right to the final puzzle. Maybe it could have benefited from "clear # puzzle, unlock the next set of puzzles" or something? The only real driving force is "Huh, wonder what the next picture will be. Maybe it'll be another Nintendo controller!"
I really do hope a sequel comes out of this, because there's a lot of potential here to build on top of this & make it better (especially presentation wise as mentioned earlier on this page).