Thank you for your feedback, it is actually meant to be a downloadable game, I just converted it to WebGL in the prototype stage to make it easier for players to access it.
The reason I am using the mouse for shooting is because I am planning to later add mouse based aiming, and it's easier to build for it from the start, it will also work with the ability system that I am planning.
The dash system is made to go through the environment as it is a navigation trick, basically it's setup to allow you access to secret areas, I do believe I have set it to bounce back when stuck in walls. So when doing the final level builds, I will build the impassable walls to be thicker than the dash.