Hehe, I love the fact the game is contained within itself; you can keep getting smaller after reaching the centre and you'll reach the outside again, and similarly you can keep moving away from the game and will end up in the centre again (the fact that there's an achievement for it was awesome).
I've got to say thhat the split in challenge mode and practise mode is not an improvement. At least, having to start at 100 all the time in challenge mode isn't. I liked being able to start at the latest 100 much better.
I know that a lot of people will agree with you but starting higher just wasn't fair... It became totally to do with the luck of the tunnels and not much to do with skill. obviously I'm open to more suggestions etc!
I hate it when a ball stops completely. You'd think it'd make the game easier, but it really doesn't. That ball becomes an annoying obstacle that can shoot off in your direction at any moment when another ball hits it. Plus the fact that it's still means some other ball took its speed and is now racing around trying to kill you.
Mounted Halberdier charges when you're playing as the Undead are so incredibly awesome. They don't even bother stopping when a guy comes up to fight with them, they just kill him in passing.
The Seekers are those bastards who start appearing in the second level and hang on to your tail to eat the things on your tail one by one. You kill them before they can grab your tail using the blades powerup to earn the badge.
Serendipity!