Yes, it is just a rhythmn/dancing game. Not too original or thrilling, but it is sort of hypnotic and has dancing cats. Not sure if I will do a lot more with it, unless I get inspired again (I have more interesting games to work on, I think).
* 1 or 2 players on one keyboard (but no interaction, so multiplayer is just parallel single-player). WASD or Arrows to control the left or right-side dancer.
* 4 difficulty levels, which can be selected independently for each player (so you can play with your nan).
* 2 dancy/chippy tunes included (both free, so not brilliant, but did I say they were free?).
* Add your own Ogg Vorbis music files to the playlist.
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Website (includes video link)
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Downloads (includes changelog)
The game is implemented in Ruby using the Gosu library.