I mean, in only the few chapters that have been released, you can already see so many similarities. For example:
Plot:

• Giant human shaped machines you control from the cockpit in the chest, that weild swords, shields and guns
• Friends fighting against each other
• people who have alot more potential with the machines than most (high magic sorcerers/coordinators)

Characters:
Lygatto/Kira = peace-loving "i don't wanna fight but somehow i got dragged into this" attitude
Athrin/Zesu = friend fighting against the protaganist because their abilities are needed for their countries fighting force
Shigwen/Kiras twin sister = royalty that has connection to protaganist (friend or sister)

But don't get me wrong, i LOVE this series (9.5/10), but so far not as much as the gundam seed anime series.

From the manga: Good Luck, Demon King!

Sure some aspects of machines give Gundam like appearence, but some are similiar to ones seen in "Full Metal! Panic" too. Ability to use magic was varying inborn skill of pretty much everyone exept almost unique unsorcerer. Coordinators were made to be superior through genic embryo manipulation.
They havent given absolute "peace loving" impression from lygatto and unlike kira who was made up super ass genic genious, Lygatto was 1 in 1000000 handicapped tomfool.
True that Zesu is oldfriend of Lygatto like Kira<->Asuran (in GS.D it was actually animated in datascreen to his name be Asuran), but Lygatto wasnt even expected or hoped to fight, just to give advice as friend.
If Shigwen had Kagalli like relationship with Lygatto, she would have hots towards Zesu, but so far his interest is in Lygatto (despite being married to Hozul).

yea, cause of the friend vs friend thing and he's the only one on this side that can fight with that machine just like Kira and Strike, that's all the similarity i've seen for now

Well, the Operating System for Gundams was yet to be finished so Kira just used his super imba skillz to write operating system in the middle of combat and boom, superhero with yber mobile suit was born. Lygatto just accidently turned machine on and barely got out from the situation alive.

yes it is true it has some similarities buts thats kinda the idea after all gundam is one of the more "known" mangas so it has some sort of success. so that being said the blue prints to a mecha good manga have been put out and to make a equally as good manga it would be wise to fallow those blue prints but change it up. its still in its begining stage where the change has not fully developed. and i say not fully devoloped lightly since its already changed when it come to how they move the robots besides the main character. and as far as big man made robots their in that sorta the idea of a mecha manga lol. their are going to man made robots. and the drama over all is their just to make it intersting it is the layout so all the asskicking thats in it can have some sort of a point and purpose. when it come to action you should have drama and enemy freinds it is what makes it good 😐

I wouldn't say 'strong' connection but there are some coincidental similarities which can be found by comparing two works of the same/similar genre.

Yeah I wouldn't say strong at all. Strong would be more along the lines of Sket Dance and Gintama.

I would also like to add that Ryugarts voice actor is the same as Kira? 😀

As side notes:
Zess = Tieria Erde from Gundam 00
Elekt = Ian Vasti from Gundam 00
Nike = Anew Returner from Gundam 00
Sigyn = Louise from Gundam 00
Hodr = Graham Acre from Gundam 00

So~
I see a very strong connection to Gundam 00?

haha wow, i didn't realize the voice actors were the same XD then again i haven't watched 00 yet, it's still on my "to watch" list x)

From the manga: Good Luck, Demon King!