Great question! Yes, the developers will also need a Spine license.
Here's how it works:
Your 2D artist owns their Spine animations and can do whatever they want with the exported data (JSON, binary, images, etc.). However, anyone who uses the official Spine Runtimes to display those animations needs their own Spine license.
Since you as developers are integrating the Spine Runtimes into your game to play back the animations, you'll need a Spine license too. The good news is that Spine Essential is sufficient for using the runtimes in your project, even if the artist created the animations using Spine Professional features.
Important notes:
- A single Spine license allows you to distribute any number of games/apps containing the Spine Runtimes
- For a free game jam project, Spine Essential should be all you need (unless your revenue exceeds $500,000 USD in a year, which would require Spine Enterprise)
Alternative: If you wanted to avoid needing a license, you could have your artist export the animations as sprite sheets or video instead of using the Spine Runtimes. However, you'd lose all the benefits of runtime animation (blending, IK, dynamic manipulation, smaller file sizes, etc.).
For a game jam where you want the full power of Spine's runtime features, having the dev team get Spine Essential licenses is the way to go!
