Kishin Taisen Gigantic Formula

Kishin Taisen Gigantic Formula and Eureka Seven have a similar feeling to me. An average boy, a mysterious girl, and lot of secrets revolving around strange mecha.  

both are the same because the main characters have special links or bonds between him and the person they are linked to, which help in fighting enemies and making allies. 

The feel is sorta the same as Xam'd. Needing to save the world, and being chosen. There's a difference in the society that they are placed, but both give the same feeling to you. 

Both Anime are Really Interesting and Both of them are Talking about the Greek Methology, Where in Gigantic Formula are talking about the Greek Gods, While in Sousei no Aquarion are talking about the Stars Signs,Zues and Angels. Well u will get the point when u watch it. Both of them are similar where they Combine to become more stronger, but in Gigantic Formula they kinda combine and use their enemy weapon or parts when they defeated there enemy. Ohh i kinda forgot to mention that, Sousei no Aquarion has more Comedy than Gigantic Formula. But Its Still Worth to Watch. 

Both series have a theme of a country supporting a particular giant robot/mech and fighting it out to see who comes out on top.