Art board of an HTML5 game

This is the Chrome Store art board for my small HTML5 game "Earthworm Ronnie". The goal of the game is to find countries on a globe.
The art board was made with Sketch, the app itself with Three.js. Here are the links to the Chrome App Store (https://chrome.google.com/webstore/detail/earthworm-ronnie/jongcofldijplcpnbdpagghchhdicoaa) and the Firefox Marketplace (https://marketplace.firefox.com/app/earthworm-ronnie).