The game board consists of a 3x3 orb grid, 1 hold slot(where the black orb is in the picture) and 1 draw slot(where the skill orb is). Note, in the picture, the player has 3 turns remaining. 2 after the player uses the skill orb.
The 3x3 orb grid is where you place orbs from the draw slot and try to make a connection (3 or more orbs of the same kind placed next to each other, but not diagonally) At the start of battle, there will be 3 battle orbs placed randomly on the 3x3 orb grid. These 3 orbs will always consist of 1 Attack orb, 1 Defend orb, and 1 random orb (Attack, Skill, Heal or Defend). The orb grid also resets itself to this state when you either manage to clear the grid completely or fill it up without making a connection. (Free draw 3 useful orbs although you can't choose where to place them)
The hold slot lets you place an orb you do not want to use yet on hold, so you can swap it out at a later time.
The draw slot gives you a random orb (out of a total of 7 kinds) to use for every hand. You can also choose to buy your choice of orb for that hand by clicking on the draw slot. The price increases each time you buy the same kind of orb, but is reset when you leave the location. A number is indicated on the draw slot. This is the number of hands you have left, or the maximum number of orbs that you can draw before your turn concludes.
Usually, you will get 5 hands per turn. For some enemies which are faster, your hands will be reduced. You can increase your hands with the Wind elemental bonus (+1 Hand), or with the elemental bonus for certain locations. Your hands can also be reduced when you get certain status: Sticky (-1 Hand per turn), Frostbitten (-1 Hand for 1st turn). If you make a connection before using up your hands, the remaining hands will be discarded (you start from 5 hands again next turn).
During the enemy's turn, it will usually perform a normal attack (deals minimum damage of 20 when you are not defending). Enemies can also use special skills which will vary from monster to monster. Defense and healing skills are cast in the beginning of a turn. Attack skills are cast after you end your turn. Enemy healing can be stopped by attacking them when they try to heal. For status inflicting attacks (attacks in blue), you can block out the status effects by defending.
The types of orbs are:
Attack Orbs: Red with the 'Sword'. 3 will do damage equal to your AP. 4+ will do damage equal to 1.5 * your AP. Price: 1500/3000/5000 coins then tokens
Guard Orbs: Blue with 'Shield' 3 will reduce the damage you receive by half and prevent one status effect. 4+ will prevent all damage. Price: 1000/2000/3000/5000 Coins
Heal Orbs: Light Violet with 'Cross'. 3 will heal you by 10% of your max hp and remove 1 status effect. 4+ will heal you for 20% of your max hp and remove all status effects. Price: 3000coins/5000coins/1token
Skill Orbs: Mocha with 'Sun'. 3 will perform a special attack for 1.5 * AP . Like Attack orbs a set of 4+ will do 2 * AP damage . Also stuns enemies. Price: 1 token/2tokens/?
Miracle Orbs: Aqua-Green with '4-Sided Star'. Can be matched with any other orb type.Turns into Dark orbs when it is not matched with two or more identical other orbs. Better save it for later if you have moves left on your turn! Price: 1token/2tokens/?
Preference: Skill > Heal > Attack > Defense 4combo>3Combo
Erase Orbs: White. Remove one orb that is already on the board...can only be placed upon other Orbs. You should stock up if they are available, but if you already have one saved in Spare Slot then you'll have to sacrifice one set Orb! Price: 3000/???/??? coins
Dark Orbs: Black. Do nothing but take up a spot on the board. Can only be removed with a Erase Orb. If you still have the extra slot empty then don't hesitate to put them there!