Slay the Spire 2 has swiftly established itself as one of the year’s most significant gaming triumphs. This widespread acclaim offers a timely moment to reflect on a pivotal decision made by its developers: the abandonment of the Unity engine.
The move came directly in response to the highly controversial developer fee changes proposed by Unity, a debacle that prompted strong condemnation from the game development community. The developers’ pointed assessment, “That is how badly you f****d up,” underscores the depth of their frustration and the industry-wide backlash against Unity’s proposed policy shifts.
Slay the Spire 2’s current success stands as a testament to its quality, further highlighting the impact of its strategic engine change.


