Modern No.2

Both are abstract and geometrical animated short films. They have a similar use of the music, and are really colorful. If you enjoyed Modern No.2, you might like Taku Boda. 

So, yes, both are just cubes moving across the screen, but Modern No.2 has colors at least. 

Both are hypnotic shorts with squares and cubes shifting shapes and sizes and such. 

Do you like to see geometric shapes animated? Do you? Sankaku no Rhythm and Modern No 2 are really the shorts for you. I feel like Modern No 2 is a sequel that decided to evolve from triangles to cubes and that you should watch.