Use the WAD or arrow keys on the keyboard to move. On touch devices use the on-screen arrows. Progress is automatically saved at the end of each level. After clicking the Play button you will be given the option to continue the previous game or reset your progress. This assumes you have completed a level previously and not deleted your browser's cache.
Max Danger Platform game. The dangers aren't always apparent so be careful. Look for a walkthrough online if you get stuck. 20 challenging levels to complete.