Slay the Spire 2 is one of the year's biggest hits, which is a good time to remember it abandoned Unity because of the dev fee debacle: 'That is how badly you f****d up'

I've been enjoying Slay the Spire 2, even if I agree with PCG's Robin Valentine that it sometimes feels like more of a remake than a sequel. But there's plenty of time for that to change: the game has only just launched in early access, and developer Mega Crit says it expects to spend one to two years building it out before a full release. Nevertheless it's already a huge hit, selling over three million copies in the first week.

I had this little itch in my brain when I was looking through the game's credits and saw the Godot logo, and then the reason why hit me: the Unity debacle of 2023, which saw Mega Crit switch engines to Godot after two years of development. I don't even think I'd heard of Godot until this.

A quick refresher: Unity attempted to attach a flat per-install fee to games that use its engine, and did so by scrapping all its existing deals and making the change retroactive. It also added a "runtime fee" that would apply to games that pass certain installation and revenue thresholds. There were all sorts of other problems, and developers showed a remarkable degree of (*coughs*) unity in coming out with public statements condemning the change, with many saying they were done with Unity entirely.

Unity initially attempted to stand firm, but was soon enough forced into a partial U-turn. And it only took a few weeks before then-CEO John Riccitiello was forced to 'retire' from his various senior roles, including president, chief executive officer, chairman and a member of the company's board of directors.

Unity remains a hugely popular engine, and CEO Matthew Bromberg has done a decent job of righting the ship, but Slay the Spire 2 shows just how much damage the whole debacle caused the company. At the time Mega Crit hadn't yet announced Slay the Spire 2, but issued this statement:

"The Mega Crit team has been hard at work these past 2+ years on a new game. But unlike with Slay the Spire, the engine we have been developing it in is Unity.

"Despite the immense amount of time and effort our team has already poured into development on our new title, we will be migrating to a new engine unless the changes are completely reverted and TOS protections are put in place.

"We have never made a public statement before. That is how badly you fucked up."

Even though Unity would end up reversing the changes, it did so in a piecemeal fashion that was never going to satisfy developers, and many ended up leaving the engine behind permanently. In Mega Crit's case that was in favour of Godot, which is offered under the MIT license, and is free to use "for any purpose."

Mega Crit chose Godot after an internal three week game jam that ended up producing a fun little deck-battler called Dancing Duellists, which is a nice palate-cleanser if you're all Slayed out: it's available for free on Windows, Mac and Linux. Mega Crit says anyone who wants to make a donation should direct it towards the Godot engine's development fund: Mega Crit is one of its major sponsors, as is Terraria developer Re-Logic.

It's a small but telling piece of recent industry history: the entire thing took maybe a month to play out in the Autumn of 2023, but by the end of it Unity's CEO was gone, the company was backtracking as fast as it possibly could, and all the goodwill it had built up among indie developers over many years was gone. Many of the developers were soon gone too.

Almost three years later, we're seeing Mega Crit prove you can build one of the year's breakout hits with Godot: and you don't imagine they'll be looking back at Unity anytime soon. Among the many criticisms of Unity's attempted changes were that they simply represented a "cash grab" on what it thought was a captive audience. As Slay the Spire 2 shows, in the long run such things can cost you.

Oh and one other thing I noticed in the credits. The lead engineer on Slay the Spire 2 is called Jake Card. Nominative determinism in action or what?