Come on, let the guy have some fun! The game is seriously intense. I recently tried this title myself and I understand your friend's perspective - the screen has a life of its own with constant flashes, stacked symbols, and rapid mode changes. And if you want to learn all the details and bonuses, check out the
how to play Only Coins online guide. It describes every detail involved, ranging from the mechanics of the sticky symbols to that of the moving multipliers. I was really fond of that feature of a coin collecting, as well as of those four bonus levels, as they were quite thrilling throughout. Maybe you'll give it a try with a couple spins and see what you think?