The objective of the game is to wander around your neighbourhood searching for Ghosts and to capturing as many ad you can. Each spooky apirition you encounter will have a set of stats that includes; Attack, Defence, HP, Crit Rate, Crit Damage, Speed and Resistance. When these stats are all accumulated together it gives you the Ghosts CP which basically tells you how strong the spectre is is overall compared with other ghosts.
Apart from their stats the Ghosts also have 3 main attributes associated with them that includes; their tier, element and rating. Their tier indicates the amount of stars they have, this will be between 1-6. There are 5 different Elements; Fire, Water, Earth, Dark and Eletric. The Ghosts rating is inidicated by the 'letter' they have on their profile; D, C, B, A and S (D is the worst while S is the best). Depending on what rating your Ghost has, gives your Ghost a bonus for multiple of its stats. The percentage bonus depends on how high the 'letter' rating is.
When you begin the game the only Ghosts you are likely to encounter are those that have 1 and 2 stars, maybe a 3-5 stars Ghost if you are exceptionally lucky. It is advised that you begin by focusing your attention to capturing the highest rating Ghost you find as this will have the highest CP. At this stage of the game it is not important that you put together a team, you just want to capture the highest rated Ghosts.
When you upgrade your Ghost's rank you will unlock more moves to use in battle and will also be able to equip it with things such as Runes. Each Ghost has a Normal Skill, Special Skill, Passive Skill, and Leader SKill. Ghosts start with their Normal and Special Skills and gains the Passive Skill and Leader Skill at rank 3 (with 3 stars) and rank 5 (with 5 stars) respectively.
When you encounter a ghost you must first lower its health until it reaches the point where you can trap it. Trapping the ghost is done by tapping the 'trap' button and holding your capture stream on the ghost to drag it over the trap. Once you have a ghost restrained you can raise them off the ground to make the 'Slam' button appear which if you then press in time will deliver a slam that dazes the ghost for a couple of seconds making them a lot easier to hold over the trap to capture them. While you are trying to capture the ghost it will try to fight back, when this happens you need to immediately tap the 'Counter' button when it flashes otherwise the ghosts attack will hit and your health will go down. If your health is reduced to zero before you are able to trap the Ghost you will lose the encounter.