The game uses a sprite map, which is an image file that contains all the smaller images and animations used in a game. If you want to edit this, you’ll want to edit the game-sprites-1x.png and game-sprites-2x.png files. The game-sprites-1x.png is used for non retina screens and the game-sprites-2x.png file is used for retina screens.
When you do, be sure that your new sprites are in the exact same place as the originals. You may have to experiment a bit with your image editor to get it right.
Also, I would not suggest editing the files in the plugin you have installed however, because if you do, those changes will get overwritten any time there is an update to the plugin.
Instead, I would suggest installing a 2nd helper plugin that will define a custom sprite map image set and make changes to the files inside the helper plugin instead. That way your site will use the modified resources and you can still update the Dinosaur Game plugin without your changes getting overwritten.
You can download the helper plugin here: Dinosaur Game – Customizations.
