I preferred the first half of Alice in Borderland because of the tone and more importantly, the challenges.
The challenges in Alice required skill, tactics and brain power, whereas a lot of the games in Squid are simply based on luck and there's one where the interference made it just stupid.
However, Alice as a narrative falls apart about halfway through. Whereas Squid Game is far more consistent (up until the final 30 minutes or so).
Both shows are worth watching though neither are a patch on Battle Royale. What a movie that is!