Handily covering our "well, that's unexpected" quota for today is Cello Fortress , a unique multiplayer gaming concept from Proun creator Joost van Dongen. Using twin-stick controls, attackers must break past defenses to destroy a base (bass?). Using an actual cello, the defending player modifies the type of guns his base wields by playing different notes and improvising a tune.

Unlike other music-based affairs such as Guitar Hero or Rock Band, Cello Fortress doesn't track scores based on note accuracy. It instead rewards creativity from the cellist as he or she composes a sturdy base defense on the fly. High, speedy notes create regular guns, for example, while ugly chords swap in flamethrower turrets. I wonder what kind of protection that jewelry commercial piece whips up.

For now, van Dongen isn't planning to fully package Cello Fortress for release—I have a feeling including one cello per sale might get kind of expensive. A working preview version is currently featured as part of a demo tour in the Netherlands, and it's unknown if tours in other countries will take place.

On his blog , van Dongen explained how his musical background influenced his decision to experiment with a game for music players, writing, "I like to make weird, unique things. How could these ingredients not combine into a game? Coming up with the actual concept for Cello Fortress was more difficult though: cello and computer can be combined in many different ways and it took me years to come up with something that is fun for the audience to play and watch, controllable by a cellist, and allows for beautiful music."