Gameplay
In the shooting games, the player's bullet power increases on a linear scale as the player collects power-ups dropped by enemies, and eventually maxes out. The player can also collect 'point' icons to earn extra lives; the number needed grows exponentially as the player gains lives. The player can use 'focus', the shift key by default, which slows down the player's movement, makes the collision box visible and (generally; some characters are reversed) focuses the player's attack to make it more powerful. The graze counter, missing from Mountain of Faith and Story of Eastern Wonderland, tracks how many bullets entered the character sprite but avoided the collision box, and rewards the player with a score bonus for living on the edge.
The player can use a weapon called a 'spell card', which is similar to a 'bomb' in most other shooting games. While the player has a limited number, using one makes the user temporarily invulnerable and uses a special magical attack that generally clears the screen. Each character has two cards with different names and patterns. The player can use one during a short period after being hit by a bullet (known as the 'border between life and death') to avoid loss of a life, the amount of time the player has available to use the border is usually around 0.3 seconds. Bosses also have spell cards, but with bosses the term applies to a prolonged pattern of movements and shots that lasts until the player depletes the boss' health by a certain amount or the time runs out, not a one-shot attack.
Each individual game of the main series after Embodiment of Scarlet Devil has additional items that affect some aspect of gameplay, such as scoring or gaining extra lives/bombs. For example, Perfect Cherry Blossom has "cherry points", which are used mostly in scoring, but can grant temporary invulnerability (known as 'supernatural border'); Imperishable Night has "time points", which are essential to advancing to later stages, and also determine if the player gets to challenge a boss's 'final spell' on normal or higher difficulties; Mountain of Faith has 'faith' points, which help tabulate the score the player receives upon gathering point items and bonuses for clearing spell cards without dying or using a spell card.
Each Touhou game has four difficulty levels—easy, normal, hard, and lunatic—with each one being harder than the previous one. Regardless of difficulty choice, there are six stages in each game and each one is harder than the previous. The only exception to this is the Embodiment of Scarlet Devil on the easy difficulty, which only has five stages.
In addition to the four main difficulties, there is an extra stage which is a long and difficult stage in which players must play through hordes of enemies, bullets, and bosses. In order to reach the extra stage, one must beat the game on normal difficulty or higher without the use of a continue. The only games that allow players to reach the extra stage by completing the easy difficulty are Story of Eastern Wonderland, Perfect Cherry Blossom, Imperishable Night, and Fairy Wars. In terms of difficulty, the extra stage is around the normal or above difficulty levels. In Perfect Cherry Blossom, there is also a phantasm extra stage in which the enemies that were already difficult in the extra stage have become even more challenging. Although the phantasm stage is aimed for the most experienced players, the difficulty is somewhere in between hard and lunatic. The phantasm stage is accessed by beating the extra stage and capturing at least 60 spells with any of the characters and weapon types combined.
Read more about this topic: Touhou Project