It seems there is a bug with the game as I cannot progress beyond killing the rat, exiting the library and getting the dialogue about the bus, but there is no bus to advance the story. So I'll give you my thoughts based on what I've played now.
Environmental design:
The fact that you can only cross roads via zebra crossing is a neat touch, but also very confusing at first because I was wondering why I could not cross the road.
The place is overall very empty and you need more animated characters. Even just NPCs that move around the park, or cars driving across the road. A few more things to bring it to life.
The lack of music really harms the overall experience as it makes the city feel more dead that it needed to be. Unless that was intended.
Battle mechanics/Gameplay:
The stance system is an interesting take on the turn-based genre and I think you're going on a good direction with this. It is a good core to build your game from and you can expand upon this idea a lot more.
What if enemies also have stances? And what if there is a combat triangle mechanic where some stances can deal more damage to enemies on other stances? Perhaps down the line, you gain skills that force enemies into certain stances. And maybe you'll get party members that can follow-up your attacks.
In the current version however, the battle feels relatively stale. In fact, there is no urgency to use the different stances. In fighting the rat, I just change my stance to the Id stance (aggressive stance) and just spam Attack and win. Without proper balancing, I can see this happening to almost every fight and may lead to uninteresting combat.
Overall:
It's somewhat lackluster in a few aspects. The core battle mechanics also feels somewhat slow paced despite your description saying 'faster-paced battle mechanics'. I think you should visit your core gameplay loop and smooth out the decision making in a turn to lead to faster battles. For example, rather than selecting a stance then selecting a move, what if you have all moves available to you regardless of stance? And using a move will change the player to the corresponding stance the move is tied to? This removes more 'lag' between input and feedback to smooth out the battle mechanics and make them pace faster.