The desktop version runs in low resolution and the web version does not detect Xbox joysticks well
Viewing post in What can I add or change to improve the game?
It looks like that the game changes your resolution. The UI isn't supposed to be blurry. I'm about to add some resolution options in the next update.
I know that the web version doesn't work with gamepads. It has something to do with the way the input system is configured. Consider the web version as a demo. It's to give you an idea what the game is all about.