Thank you for the feedback.
I will change the mouse pointer to only be captured when the window is active, good call.
An options menu to invert both axis will be added down the line. I may add a temporary UI solution soon down the line because its a highly requested feature.
For gameplay and controls. My plan is to add simple tutorial playground area that teaches the player the basics on controls before the first level. As I feel it would be hard to cram tutorials everywhere into such a small level that already has a lot going on.
Buttons prompts are designed with an Xbox controller in mind. I am unsure if Stadia uses different standards compared to Xbox so the icons may be different.
For the pinball controls does R2/L2 (or left/right mouse button on keyboard) for each flipper sound better? I think that would work better as a more accurate pinball experience. Not sure what I could bind the launcher to, maybe holding down?