This was a 3D-animated show that would air in the mornings on Cartoon Network around 2014-2017. Around the time of Teens Titan Go. It was promoting some toy being released around that time if I remember correctly. The characters were all rectangular (long ways) and would bounce around in order to walk, pretty vibrant and random show. There weren't really any "episodes", more like shorts, and each were only about 5 minutes long and would air before the regular programming.
I think this show only aired for literally just a month or two, since it was pretty poorly made and obviously only made to promote the toy. There was probably only like 3 or 4 of these shorts ever made, and they would always cycle through these ones. It kind of just came and went, which is probably why I can't find it in the lists of Cartoon Network programming.
The show itself was not one of those educational block shows for toddlers. It was very much focused on action/comedy and on promoting these toys.
The only short of the show I remember was in this metropolitan city in the park. There was some kind of alien invasion or something and the block characters fought against each other. If I remember there was also a samurai or ninja character with a sword.