Right mouse button is a terrible choice for webgames as on many browsers you accidentally end up closing the tab or opening a new tab. Right mouse click, and ideally left mouse click, should have an alternative available on the keyboard.

The motion of the paddle is slow, which other people have pointed out, but I'd also say it feels both jerky and slippy, which detracts from the experience.

You've got some interesting ideas here, but the I don't think most players are ever going to be able to interact with them. There's the fore issue of the paddle moving much more slowly than the ball meaning that a high level of mastery is required just for basic play, but also you don't start with any specials, making it very difficult to get a high enough combo to actually unlock any specials

The paddle moves so slowly in which it is very difficult to try to navigate and line up under the fast-moving ball, which could ricochet very quickly at steep angle and makes it impossible to reach. You would get a lot of Game Over screen with this before anything remotely interesting happens. And once anything interesting happens, the game become quite interesting to play with the power-ups and bullet-time mechanic.

I believe the problem lies in the conjunction of slow-moving paddle and the bullet-time gauge in which it takes a while to build up the meter in order to use it effectively. Increasing the speed for paddle would remove large degree of frustration and difficulty and having the gauge being used more efficiently with one block hit equal one-half second of bullet-time instead of waiting to use it after 3 or 4 block hits. This way, the player would be in better position to avoid getting game over and you would reward the player's effort by keeping them invested in this game.