so if u see the anime and u thinks is gud or decent or maybe bad but dont hate it.
Then see this.
this is really the much superior adaptation and the issue of making japs such a gud guy, is better handle here they are not dat good in the manga.
so give a try from the first chapter, i know is alot but trust me lots of extra scene that were cut from dat anime.

but if ur new well if u like military or isekai or wondering how if we invade a under develop civilization what it would look like or if u like isekai and reverse isekai (other world come to our world) then u will like.
but warning, some scene are abit gory but nothing a teen past 18 cant handle. (i think dont sue me)

story
so story well is written above is basically dat and major plot are the same with anime. But whut ur looking in the manga is the little detail and extra things, like they cut alot of arch and scene from the manga. But the plot it self of having a gate establish in two world are really interesting it. Could be a isekai and a reverse isekai since both worlds are open at all time.

art
the art are detail, lots of extra detail and scene were present here. Like the city, base and alnus (the gate entrance of the other world later turn city) itself were much more detail and interesting

character
its as bland as it can be but, better than anime more backstory and archs. But it always be the weakness of the series. U got the bland otaku mc, the goth loli demi god, the moe loli magician, the big oppai elf and the ehm sl4v3 dark elf. The rest of them, the mc comrade are rather bland too. But comapare to anime here they got more scene. U got the muscle short girl as the melee fighter, the old vet (by old vet mean old in the army so like a grandpa character), the cute medic girl, the otaku comrade, the smug looking superior and the calm general. on the villain side, u got the mostly one dimensional but really hate able prince. As the douche-bag villain, the unwise kings and the smart but never listened to princess.

enjoyment
the enjoyment is always lies in the world building, battles, seeing the mc faction kick-ass and feeling human as superior (in tech), or the reaction of the character seeing advance tech or cute cat girls. but like overlord they handle the op of the mc faction quite well. Instead of "ah they too op is be over soon." But since the villain are such jerk u will be "oh time to f*ck em up"

conclusion

basically read it if u like the anime or if u think is decent, if u hate it then dont ill be pushing u. If ur new if u like military or isekai or wondering how if we invade a under develop civilization what it would look like or if u like isekai and reverse isekai (other world come to our world) then u will like.