Coins are spent to upgrade power-ups. Besides earning coins during game play, you can watch advertising videos.
Credits
You can play the game even when you do not have any credits, however you will not be able to use power-ups. You can advance the time on your device to restore all your credits or immediately upgrade your power-ups. Then, set the time back to its correct value.
Dots
You will earn score multipliers for collecting a specific amount of dots (16, 32, 64, 128). You will also get a super bonus if you eat 256 dots consecutively, which will destroy all the ghosts on the screen at that time. Skipping a dot will reset the counter.
Fruits
Eat fruits when they randomly appear to activate score multipliers to earn more points. Each type of fruit gives a different multiplier. Cherries give you 60 points and a 2x multiplier, while the green fruit will give you 180 points and a 6x multiplier.
Portals
When passing through a portal on the edge of the screen, Pac-Man will briefly become invincible. You can use them when you are in trouble, however they will remove the effect of a pellet.
Upgrades
Spend coins to upgrade your power-ups. Focus on those that you use frequently. Keep upgrading them until a better one is unlocked.
Various Game Center Achievements
Complete the required tasks to unlock each Achievement.
Coins...