Theme number two "Heavy Blues" is a blue-grid floor with a squarish background and a heavy blue ball.
This theme is basically stress testing a couple of elements in the engine.

You can Play Heavy Blues over at SpikeDislike.com

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The Main Tests

1. That I can hold and display multiple themes in one single spritesheet.
and
2. That I can easily tweak ball physics.

Results

1. Kinda, but not quite. The framerate seems to be suffering on lesser devices. I think the fact that I'm now using >1024x1024 spritesheets (16 themes on a single spritesheet) is making it a bit "too" complex for some browsers.
I'll likely retweak it to be 512x512 sheets (4 themes on a spriesheet) instead.

2. The ball physics changes worked great, and the ball seems to sync up well with the new choon which is at 180bpm, instead of the usual 140.
The game's a LOT harder with these physics, though, so don't expect to get a great score in this mode.