In my opinion, season 1 is a whole lot better than season 2. Mostly because the games in season 1 were more exciting and I wasn't too fond of the last 2 episodes of season 2.
With that being said, that doesn't mean that I disliked season 2. I just liked season 1 (for which I gave a 9.5 out of 10) better.

Things I loved about season 2:

- All the games Chishiya was involved in
- The King of Clubs game (the very first game showed)
- Kyuma's wardrobe...;)
- The backstories and flashbacks
- How even the minor characters were brought back
- The explanation for the mystery of the Borderland in the last episode

Things that frustrated me:

- Niragi never dying. Gosh that pest was the worst!
- Would have liked to see more games like in season 1
- 7th episode was so frustrating! Was almost impossible to kill the King of Spades, even after him being shot properly multiple times. And almost everyone else (other than Arisu) being seriously injured (and some even looking as good as dead) but not dying. Although the whole episode was action packed and not boring, the whole thing was extremely unreal.
- The last episode just felt too draggy and the Queen of Hearts game mostly gave me a headache lol

The ending explanation was satisfying but with the revelation of the Joker card at the end, feels like there might be a season 3. If they do make a season 3, I'd definitely watch it!