It is just not a good looking park. Trees will definitely help, but it's not just lack of vegetation. Celestial Park is beautiful and will continue to develop into a more pleasant space to hang out when trees grow in. I just don't see that happening here. There are multiple attractions (Shrek, Minions rafts) that have you spending a lot of time looking at bare walls.
Before they let us into the park, they said something to the effect of this being a gateway to the immersive themed environments Universal is known for. If that was the goal, they failed. There's nothing in this park that would make me think I've gotta see what else Universal has cooking.
The type of theming and vibe they have here reminds me a lot of the Nickelodeon Universe park at Mall of America. That is ... not a compliment.