Both "Terrorarium" and "Bubble Trouble" had far better concepts than most episodes of 'My Little Pony: Pony Life' and had potential. Especially "Terrorarium", always do like episodes with some kind of monster like character and lots of chaos. "Bubble Trouble" also had a nice premise, though was worried that Spike messing up would be too like the way he was written in early seasons 'Friendship is Magic'. Luckily it just about avoids that trap.
Character moments and writing wise, there is a noticeable improvement here and in the previous episode compared to the first season (though neither are perfect still, far from it). And both segments are among the best, or more like among the least problematic, episodes of 'Pony Life' (especially "Terrorarium"). Neither are particularly great either, with the stories not being strong enough and the quality of both are inconsistent. Inconsistent is at least a good deal better than mediocre or downright weak like most of Season 1, but both could have been so much more.
There are things that both segments do well. A vast majority of the voice acting is fine, Asleigh Ball gives it her all as Applejack in "Terrorarium". The characters are at least in characters and have some likeability, did appreciate that Applejack was not too stubborn and that her humour wasn't too forced and "Bubble Trouble" doesn't overdo Spike's character flaws or have characters mistreating him. The character interaction isn't disconnected.
Some nice animation touches here and there can be seen, notably the bubbles and even more the plant, who is a real pest while not being obnoxious. There is also here a little more humour than usual and some of it amuses. They both start off very well.
Both also could have been better, especially "Bubble Trouble". "Terrorarium" could have done with more thrills and excitement, with it thinning out towards the end and becoming predictable. "Bubble Trouble" is very thin and over-stretched as well as too repetitive. While the morals are very well intended and are not laid on too thick, they are also very rehashed and have been done before and better on the infinitely superior 'My Little Pony: Friendship is Magic'. While the writing has a little more spark than the usual 'Pony Life' episode, it is still too bland and too simple.
While the character writing improves vastly here, it is still too simple and stereotyped while the supporting characters are largely unmemorable. The animation lacks imagination and looks rushed on the whole, and the music is high school quality with a grating theme tune. The new voice for Spike doesn't do it for me, it just doesn't feel right without Cathy Weseluk and the new somewhat too hyper voice doesn't fit.
Overall, better than most episodes of the show but neither come off as well as they could have done. 5/10.