Tengen Toppa Gurren Lagann, Heroic Age Recommendations
It's similar with saving Earth along with mechas..
Both of these anime are about humaniti fighting against some alien force to survive and also awesome space battles.Age and Simon are somewhat similar too and heroic age's story reminded me a lot to tengen toppa gurren lagann.
I feel like both of these anime have a fast pace plot line and have an epic feel to them. I loved both of them and I feel like if you liked gurren lagann you will definetly like all the action and epic story line of heroic age
They are similar because the people are trying to save there home work from being destroyed an on the way the fined some one/some thing to help them win the battle for hope.
Both have great outer space action, although only the latter half of Gurren Lagann is based in space. The main characters originated from a seemingly barren planet, and need to fight aliens in order to protect the universe. Both main characters are overwhelmingly powerful when they are using their mecha.