You have to match a minimum of three symbols to remove them (and some tiles underneath). It of course replenishes gradually, and your objective each time is either:
(a) to remove tiles and/or some some sorcerous heads that climb upward while you try to drag them downward in order to remove them (removing the icons that prop them up, they'll just drop out), or
(b) clear the board of its tiles in a limited time. In order to play, you get either a limited number of moves or a limited amount of time to finish the task.

Some obstacles will also be put in your way, like stone heads that create gradually obstacles in cleared space, or spheres that chain and freeze the symbols you are trying to match in order to progress. You accumulate gold pieces along the way that may serve to buy bonuses whenever you feel the need to, some can be bought while playing a level, others must be bought before starting a level. You may accumulate up to three stars for each level, in relation with your accomplishments in the game. These stars do not bring any benefits though. The progression yields basically the following results:

Match 3 = remove 3 linear symbols

Match 4 = replace 4 matching symbols by one arrowed one

• Arrowed matched with 2 same symbols removes column / row
  
• Arrowed matched with Arrowed removes column + row + nearby symbols

Match 5 = replace 5 matching symbol with a bomb

• Bomb matched with 2 same symbols explodes the nearby area
  
• Bomb matched with another bomb = bigger boom

Match 6 = replace 6 matched symbols with a neutral coloured wheel

• Coloured wheel has various effects:
  
• - wheel + symbol = removes every identical symbol from the board
  
• - wheel + arrowed = transforms all same symbols into arrowed, then boom!
  
• - wheel + bomb = transforms all same symbols into bombs, then megaboom!
  
• - wheel + wheel = cleans the whole board

Note: the 6 symbols may be in a line, T shape or L shape

• Chain reactions will happen...