It is my opinion that if one wants to get good at Aikido, they must master the footwork. Footwork in the Japanese martial arts is called ashi-sabaki (足捌き). Some teacher focus more on tai-sabaki (体捌き) or whole body movement, but to me foundations begin from the ground up. To me there are only five footwork movements in Aikido that consists of: forward and backward tsugi-ashi, forward and backward ayumi-ashi and tenkan or turning. Some think that there is a sixth, but I don't personally count side stepping as a form of footwork since Aikidoist employ the hanmi stance. Rightfully, many don't focus on footwork because what is really happening is that the hips are moving in Aikido, but for me the hips are driven by the feet. So I don't want to jump the gun and have students focus primarily on tai-sabaki because if their footwork is bad, their hips will be bad and thus the whole body movement will be out of sync.
If you don't think footwork is where it is at, here is a video of the great Ronaldinho and you can see how he destroys his opponents with his excellent footwork.
https://www.youtube.com/watch?v=a0ksVaLlaIw