haha brilliant!

but why is this licenced under 5 different licences? surely 1 should suffice?

yeah, cc0 makes all those other licenses pointless...

CC0 allows relicensing, so if you choose than one others are redundant.

I built this for my 4th grade math students to learn plotting on the coordinate grid:

http://scratch.mit.edu/projects/20047731/

It uses your sprites, although, I found that the aircraft carrier needed to be stretched horizontally; there was too much transparent space on the ends to work properly in the game, using pixel detection.