mmm... The game lacks a good cavern music, it doesn't have a jump sound, and the remaining sounds, such as those of catching coins or killing enemies, are a little too intense and don't faithfully represent the pixelated style of the game. Keep in mind that sounds and music are important for your game developing.
Chrome: https://chrome.google.com/webstore/detail/free-games/gechcfjojodafcpggkekfkkfpjacenno
Mozilla/Firefox: https://addons.mozilla.org/firefox/addon/indie-games/
Opera: https://addons.opera.com/it/extensions/details/free-games-2/
Click and Play!