The following changes/enhancements have been implemented:
1) a new hybrid structure of challenges to make it possible to attempt any undone challenges on the same lateral level.
2) re-playing of solved challenges
3) addition of Rank info on the top right panel
4) adjustment of Done info (previously, it shows one level higher than the number of challenges completed. This had proven to be confusing, as experienced by kenshiro)
5) removal of the applet news - with the new scatter structure, the customised message at each level doesn't make sense any more.
6) css upgrading
Note that if you've done all 30 challenges, the pyramid image will show the next level challenges as available when in fact they are not. This is not a bug but a feature of the hybrid structure.
Cheers and merry Christmas to all!