Being a casual logical game, "15 Defense" challenges the player to destroy a sort of adversary’s fortress (in this case, to defeat the Octopus) while defending themselves from enemy attacks by moving a special "Shell" unit or by moving the game units so that the place the enemy is attacking gets empty. Movements principle is the same as in "Fifteen Puzzle".
There are some engaging peculiarities yet. The gameplay of a famous logical game is enriched by arcade gameplay elements: enemy’s attacks and enemy "bombs" hitting player’s territory. It triggers players to make decisions and move units faster to avoid enemy’s attacks.
The player moves their game units across the field seeking to recharge special action units ("Jellyfishes") and avoid being hit by enemy attacks.
There are various skills (abilities and bonuses) like de-freezing game units, freezing enemy for a short time, destroying the attacking "bomb", etc.
Features:
• Challenging gameplay.
• Endless game ("Survival" and "Waves").
• Variety of ancillary skills.
• Mischievous foes.
• Table achievements - to fulfill the mission.
• Opportunity to improve its own record.