KSP2 was released in Early Access for $49.90, after being delayed three times. Originally announced at Gamescom in August 19, 2019 with a 2020 release date, it was pushed back to Q3 2021, and later in 2020, Nate Simpson, the game’s creative director, announced that the new release date would be in 2022. In May 2022, a YouTube video posted on the official channel announced that the release was pushed back again to "early 2023".

The early stages of the game’s development was surrounded in a controversy, as the game was initially set to be developed by Star Theory Games. A report by Bloomberg revealed that there were disagreements between Take-Two and Star Theory, which resulted in Take2 cancelling the contract with Star Theory and trying to poach most of the developers that were working on KSP2. Take2 created a new studio, Intercept Games, with a bunch of employees from the previous studio. Star Theory shut down its doors three months later.

The developers acknowledged that there were some issues during launch, for example, missing parts from KSP1 and lack of re-entry and thermal heating system (and their respective visuals). Players experienced extremely low performance with top-tier gaming rigs, others experienced "bringing the entire KSC with their vessel" when launching a rocket, random ship explosions and other bugs that prevented one from having an enjoyable gameplay session.

A few weeks prior to the launch, Take-Two and Intercept Games, together with the European Space Agency, organized an event and invited several youtubers and content creators to try out KSP2. Some creators pointed out a lot of critical issues that the game had during this test, which, surprisingly, weren’t caught by the QA team and fixed by the Early Access launch date.

Although there was no other official communication, creative director Nate Simpson was actively replying to users on the forums and trying to convince them that the critical bugs would be fixed by the next patch (he didn’t give an ETA for the next update).