Added touch support, introduced in iOS 2.0 (2008), so that it works on
mobile devices and tablets. Otherwise the code is identical to the original page from 2006. It still works today, a
testimony of my awesome programming skills the Web's
backwards compatibility — add new stuff, but never break old
ones.
Ravensburger no longer has the game online in JavaScript form, but this seems to be a copy of the original code. It even only works in IE!
Puzzles 1 to 3 are warm-ups. Puzzle 4 onwards are brain-burners. Let me know if you find a difficult-to-solve puzzle!