This is just my opinion and I don't know if everyone will agree, but I found 2 significantly easier than 1. I 100%'d 2 and I think only one of the bonus puzzles really took me much time. I didn't get the achievement for taking 20 or 30m, whatever it is, until one of the final bonus puzzles I was doing. You can play 2 without having completed 1 also, but knowing the story of 1 (and the DLC) does enrich 2. It might be worth a try.

(Your experience of 2 might be totally different. I love puzzle games and completed all of the bonus challenges of vanilla 1 and 2. I may have just thought 2 was easy from having experience or even that the puzzles clicked for me better. Just take any opinion of puzzle difficulties with a grain of salt. Everyone's brain works differently.)