In short:
The game now makes the experimental head steering a bit smoother and more configurable. Also the game is now fully playable with VR controllers.
The changelog in detail for version 0.9.1 is all about Virtual Reality:
fixed VR-ingame-UI Z-ordering issue
better position and size for ingame-UI in VR mode
switched font for better readability in VR mode
player can move in Z while ingame in VR mode
player can move freely when game is paused or between levels / ship losses
experimental: tried to optimize ship head-steering/movement versus ingame-UI:
UI standing still around player which seems to interfere with player expectations when
enemy field and player ship move quite fast
amount of VR head-steering is configurable in settings
experimental: slowed down enemy movement in VR-mode
added VR Virtual Keyboard for local highscore input
added VR Controller thumbsticks and buttons to steer and use UI, idea: use both controllers like steering a plane
Have Fun!