Yes, it seems the level of this series maxed out in Season 1. Not that this season is horrible. It's just kinda 'meh.' The expecation going in was, it was going to keep getting better.
The artwork is about the same as season 1. Cute, but nothing spectacular, only average. I'd say the background work has dropped off noticeably. Animation definitely took a hit. It was never spectacular, but so far this season, I would call it a bit less than average. Especially since ep 3, there's been a lot of cost cutting showing up.
The first season succeeded because of the characters, but there's not really much going on with them this season. Adding more characters to the mix has only thinned out the soup, and they are little more than cardboard cutouts. Even characters from the first season have become very 2D.
Points to a deep tail off in the writing. The blue dragon ep was interesting. But other than that, things have been kinda blah, and unmemorable. And a beach ep? Never thought this title would drag out such a lame, tired old trope. A present for the fan service crowd, I guess. But even at that level, it wasn't much.
The VAs are still doing a decent job. But it's not been to the level of season one; an indication of subpar work by the direction.
I wouldn't burn this one at the stake, as it still is mildly amusing. But while the grade for this started out as a B, it's been slowly and inexorably sliding downwards. I would give it no more than a C at 74/100 now. I'll keep watching until the season ends, but more to see if it can keep from slipping into D territory than anything else.