because the developers sucks

Cause to license it will be more expensive than whole game's budget.

KomdivCCCP の投稿を引用：

Cause to license it will be more expensive than whole game's budget.

If they have the license to use the anime, how can they not have the license to use the music in the anime?

Because music must be licensed separately. How often do you hear original soundtracks in anime licensed games? For example One Piece?

real

The Beast at Tanagra の投稿を引用：

KomdivCCCP の投稿を引用：

Cause to license it will be more expensive than whole game's budget.

If they have the license to use the anime, how can they not have the license to use the music in the anime?

Made in Abyss was originally a manga. Why would they go to the ones responsible for the anime adaptation to request a license to adapt the manga? LOL Even if they did get permission (which duh, they did, otherwise this game wouldn't exist), that does not automatically mean they have the license to use the music nor the composer's consent.

basically blame the music creators for making good music and also not allowing it to be used

Eoun の投稿を引用：

also not allowing it to be used

They most likely would have been granted permission, but it'd cost not only money to pay the original composers money, but the composer would also have to rework the songs to function / flow in a game format, or resort to recreating the soundtrack in the game that would work but keep the feel of the show's soundtrack which is ⌚ and 💸.

Not saying that couldn't be done, but Spike probably didn't see it as feasible.

theres a mod for that, and you see why almost right away : the music makes good background music for scenes, but it dosent fit the game at all and makes everything feel extra dissjointed.