The first level is build using six numbered bags... although that's slightly off, since most numbers have multiple bags. It's a LOT of pieces. Not a lot of vibrant colors on this level; the buildings are mostly brown and white, with gray, dark tan, and olive green built into the base. The water uses a TON of trans blue tiles, which itself was a mighty task to put down properly, but the instructions weren't too bad. The water itself is a cool design, because they have different colors underneath the tiles, giving a vague idea that there's a waterscape below the city. (An interesting bit is that trans neon green was used as the base beneath the sewer... so take that for what you will.) There have been a few unusual parts here and there, so this does make for a good parts pack, but hopefully some of the newer, rarer elements will start showing up in cheaper sets.
The first thing that surprised me was how small the set's footprint is. Others have commented that it's only on a 32x32 baseplate, but at least a third of that is already taken up by water tiles, so the entire model is build up on three corners of a baseplate. There's already a lot going on the first level, as you have the clean up robot's storage area, the fish market, a small bedroom, and a tea house, as well as a cool bridge and the start of the elevator. The individual rooms are rather small, but have distinctive looks to them. It does remind me why I decided to avoid module buildings; there's a lot of detail packed into them, but they're hard to look in when the set's build, and even harder to access due to their size. (The cleaner robot's storage room is particularly irksome to access.) There are some nice details, and I especially liked the green Sabine hairpiece used as a plant. Some of them also have distinctive roof designs, but my favorites so far is the design using the crowbars. (Did that crowbar piece always snap onto a bar like that? Was I seriously missing their potential?)
The water is mostly tiles, but there are still a few studs popping out, either as plant life (the paint palette as a lily pad is great) or as 1x1 plates (to fit in the corners that the 1x2 tiles couldn't finish.) On one hand, that means the boat can't be slid along effortlessly through the water, but then there are also some connection points for it. The boat is an awesome little design, and I really like how they built the cover. (I mean, it doesn't feel like it's minifig scale, but I can let that slide.) They also included a neat dock on the back using brown technic connectors. The bridge is also a great design, and I'm impressed at how they designed the angles rails. Previous sets have used the clips, but they leave exposed gaps and sometimes aren't secured in. Well, they cleverly used the neck brackets to hide the gap, and the balljoints secure the tile at the bottom. The elevator is also a simple but effective and modular design. I skipped ahead and build the elevator stand, and it works great. There's also the small tower on the far corner, which is okay but the cooler part is the design they used to anchor it at the 45 degree angle, which is something we don't usually see in system sets.
The figs are... well, they're not exactly the highlight of the set. Three figs have traditional Asian robe designs... that are seen in a lot of the Ninjago sets, wore by various civilians. Civilian Kai is great, mostly because he completes my civilian ninja collection, but the actual design is still pretty meh. I guess the best here is Ivy Walker, with her colorful torso design. (I thought she might be Jay's sister, since his last name is Walker on the TV show, although he doesn't have siblings. Instead, maybe she's his Aunt, and little Sally is his cousin?)
One thing I don't usually look forward to in sets is the stickers, but this one is an exception. Only, the ground level doesn't exactly have a ton. The two tiles along the bridge do reference Bionicle (they were the first stickers applied too) but sadly they're partially hidden by the plant life. My favorite here would probably be the kimono lady design on a door panel, but the tiger poster in the tea house is also well done.
There aren't really any fun play features on the ground level, although I know we get some as we move up in the set. I guess there's the elevator, as well as a few sliding door panels.
In conclusion, the bottom level is a solid design, and is sturdy enough to add more rooms to the top of this. The room designs are okay... some would be nice as their own mini set. The highlights so far have been the boat design, the crowbar roof, and the stone bridge design. I'm eager to build the next level and see what cool designs are waiting there.