Always check the asset’s documentation. Some assets require a specific project type.
You can change the camera to orthographic, import sprites, and add 2D physics — but the project remains “3D” under the hood. If you started in 2D and want 3D features, you’ll need to add 3D components manually (camera perspective, 3D colliders, lighting). unity 2d vs 3d project
Choose 2D when:
Unity supports real-time shadows, global illumination, and complex shaders. Light bounces off surfaces and interacts with 3D geometry. While beautiful, this requires a lot of processing power. Always check the asset’s documentation