Puniru is a Kawaii Slime Season 2 is very similar in it's strengths and weaknesses as Season 1, however I'd say it just barely pulls ahead of Season 1 overall. You still get the comedy Puniru has been known for since the start, and just like Season 1, not all of the jokes hit. Though I personally felt that more of them hit here this season. Although that is rather subjective and your experience may vary it might still be worth considering.
This season's biggest strength is it's character development, focusing a little bit more on Puniru and Kotaro's friendship and backstory than before. It enables this season to have a bit more additional "selling points" if you will to help keep the season entertaining even when the jokes don't always hit.
Overall the verdict is the usual one for shows with "good" sequels. If you liked Season 1 you'll probably like Season 2, if you didn't like Season 1 you probably won't. Puniru is a Kawaii Slime is a rather unique take on gag comedy that I'd say is working out pretty well on the whole. 8/10.