The Game‘s companysays his record label promised a half-million bucks to push his album “Drillmatic — Heart vs. Mind” … but claims it left most of that money on the table and the album sales suffered as a result … TMZ has learned.

In a new lawsuit, obtained by TMZ, The Game’s company, 100 Entertainment Inc., says UMG and Virgin Music agreed to put $500,000 behind marketing and promotion for the 2022 album.

The suit says both sides signed off on a detailed budget allocation just days before release … with money set aside for videos, digital ads, overseas promotion, and $125,000 for radio.

But The Game’s company claims only about a third of the money was actually spent … leaving more than $320,000 unused.

It says none of the $125K earmarked for radio was spent, and claims the money that was used was later recouped from The Game’s royalties.

The company claims the weak rollout hurt the album at the most important time — right when it dropped — and says “Drillmatic” would have done better if the full marketing budget had been used.

The album reportedly sold the equivalent of about 25,000 records in its first week and debuted at No. 12 on the Billboard 200.