Is fighting on inclines, or changing terrain possible with the Z-Engine?
People already brought up a few examples, but remember you can also just fight the Hungry Ghosts on the slopes and stairs at the start of the Prototype stage too. Some of the recent clips also show battles on uneven terrain. Safe to say, as long as Ajna can stand on it, you can probably fight on it.
In the Prototype, you can also juggle enemies off of ledges to end fights early, or get knocked off one yourself. I'm pretty sure in the finished game we'll see hazardous terrain play a factor as well. No idea if they'll feature battles on moving terrain, but technically it's all possible.
Another thing I'm worried about is how much content is Indivisible planned to have?
Like a lot of folks here, I've been using Chrono Trigger as the benchmark for Indivisible. LabZero's referenced it multiple times, and it really does seem to embody a lot of what they're aiming for in terms of overall tone and pacing. If you imagine CT's dungeons playing out like a platformer, I think you can get a good sense of how the story and gameplay content might flow for Indivisible.
On the topic of enemies, I figured I'd look at some lists of CT's enemies to compare to the progress on Indivisible. Not counting bosses, or any palette swaps, it looks like CT featured a little over 50 unique enemy sprites that were remixed in various ways to fill its 20Hr avg playtime. So far with Indivisible, we know of roughly 18 unique enemy types not counting known bosses. So even with a lot left to do, and a lot of unrevealed material, it looks like they're nearly at the halfway point as far as CT's concerned. Considering how much LabZero can do with rescaling sprites/hitboxes in addition to palette swaps, it looks like there should be a good amount of enemy variety in the end.