The old homescreen and other stuff remains but the player UI has the following changes:

1. The play/pause button is now round.

2. There is no previous/next button but a thumbnail of next video below the progress bar.

3. The closed caption (cc) button is now in player directly (was inside settings). Sadly the video quality selector is still inside settings.

4. While playing an ad, the video length is at top and skip button is now solid.

5. The progress bar is more precise and bigger.

By the way mouse navigation works for me since last update so you can skip video to wherever you want.