Here's an [official source code](https://github.com/pixeljam/DinoRunDX) published by the developer of [Dino Run DX](https://store.steampowered.com/app/248330/Dino_Run_DX/). The open source announcement is [here](https://store.steampowered.com/news/app/248330/view/3639504956058288978).