Colossal Order CEO Mariina Hallikainen has acknowledged that the studio "completely overestimated the engine's capabilities" at the beginning of the Cities: Skylines 2 project. The admission arrives months after one of the most troubled launches in recent simulation gaming history, exposing a core tension in modern game development: the risk of building on cutting-edge technology before it's ready for prime time.
The Finnish developer bet its sequel on Unity's new DOTS (Data-Oriented Technology Stack) and HDRP (High Definition Render Pipeline) tools. On paper, the architecture made sense. DOTS was meant to fix CPU bottlenecks from the previous game and increase the scale and depth of the simulation, and largely succeeded on that front. But the rendering side proved far more problematic.
Colossal Order had to implement much of the graphics work themselves because Unity's integration between DOTS and HDRP was still a work in progress and unsuitable for most games. Similarly, Unity's virtual texturing solution remained in beta, forcing the studio to build their own solution which had teething issues. When you're building something as complex as a city simulator with hundreds of thousands of objects on screen, gaps in a core engine aren't minor inconveniences; they're development killers.
The performance spiral
The result was immediately visible at launch in October 2023. The game threw far too much unnecessary geometry at graphics cards, due to both a lack of simplified LOD (level of detail) variants for many meshes and a simplistic, untuned culling system. In plain terms, the game was rendering objects at full detail even when players couldn't see them properly, and failing to switch to simpler models for distant objects.
The performance issues were so severe that console versions scheduled for October 2023 were delayed, with preorders closed and existing preorders refunded. On PC, the game became notorious for demanding high-end GPUs even at lower settings. Colossal Order and publisher Paradox Interactive later parted ways, with Iceflake Studios stepping in to continue patching the game.
Hallikainen said, "Our mistake was to bank on something that was not yet proven." But she also offered a more nuanced picture. Despite the difficulties, Hallikainen said Colossal Order doesn't bear ill will toward Unity, noting, "We have a great relationship" and "everyone at Colossal Order, Paradox, Unity, we all did the best we could under the circumstances."
A familiar trap
The Cities: Skylines 2 episode reflects a broader problem in game development. Studios often face pressure to ship products even when critical systems aren't ready, gambling that post-launch patches will fix what development deadlines couldn't. The bet rarely pays off cleanly. Players buy incomplete products, reviews tank, and recovery takes months of grinding work.
What's notable here is that the root cause wasn't incompetence; it was a timing problem. Colossal Order started the game when DOTS was still experimental, and it came as a surprise how much they had to implement themselves even when DOTS was officially considered production ready. The technology evolved as they built on top of it, forcing constant pivots.
Colossal Order is now working on a new game in the simulation genre for PC, once again using Unity. Whether they've learned to wait longer for unproven engines to mature remains to be seen.