Is Cosmic Fantasy 3 mechanically very similar to 2? As in broken?
Not that I remember, but it's very different. There isn't as much of an overworld map, you walk around like an adventure game. Enemies are super over the top cartoons and the characters don't seem very memorable. The battles have black backgrounds and huge character portaits. The map bgs still make heavy use of that pointillism style. CF4 has top quality 16-bit visuals though.