Note: I haven't watched the whole series yet.
Gad Guard impresses me mostly for what it accomplishes despite its origin.
It has no following. It wasn't popular. Barely anybody knows it exists.
It's a retro sci-fi action series. It stars teenagers who literally stand on the shoulders of Gigantor-style giant robots.
But there's no invading alien armada. There's no robot uprising. The protagonists pursue their personal goals, and occasionally fight each other. There's surprisingly little evil anywhere. It's just...people with conflicting goals.
Each protagonist has his or her own mecha, which reflects that character's past or perspective. The primary antagonist--a very serious, nihilistic young man--names his mecha Zero. A perfect tool for a man who trusts nobody.
Meanwhile, each episode reveals a little more of the characters' motivations. Just enough to make me nod and say, "Ah-ha." Just about every single episode does this. So rare in anime.
Is it flawless? No. But it's awfully good for what it is: a fun shonen action show of teenagers and their giant robots.