Frontier Developments, developer of Planet Coaster, has sued Atari over alleged unpaid royalties for RollerCoaster Tycoon 3, which was made by Frontier and published by Atari. TMZ broke the news, in which Frontier claims it is owed over $2 million dollars that has gone unpaid.

Atari filed for bankruptcy in January 2013, and Frontier stuck with them and amended their contract for 2004’s RollerCoaster Tycoon 3. Frontier claims they have been paid $1.17 million, but suspect sales amounted to $3.37 million in royalties, leaving a wide gap in what they’ve been paid and what they believe they should have been paid. Further, it is also alleged that Atari has denied Frontier their contractual right to audit these numbers. COO for Frontier, David Walsh, told EuroGamer Frontier has “attempted to resolve this issue without legal action since April 2016. We have so far been denied our contractual right to audit by Atari, and we are unfortunately left with no other way to resolve our concerns.”

Atari’s plan to recover from bankruptcy was approved in December 2013. This quick turnaround may fuel Frontier’s suspicions that Atari’s reported numbers were less than truthful. Suspicions aside, the relationship between Frontier and Atari could not have possibly been helped when Atari hastily released RollerCoaster Tycoon World one day before the scheduled launch of Planet Coaster. Atari’s new coaster sim has received mostly negative reviews from users on Steam. Many of those reviews consider the game to have been released in an unfinished state, purely to try to cash in ahead of Planet Coaster, which has very positive reviews on Steam, and was given a top 5/5 score here on VGN.