The game may be played using either a keyboard or a gamepad.
Keyboard controls are as follows:
- The Arrow Keys move the character around
- Z causes a short barrage of shots to be fired; it may be held down for rapid fire
- X releases a bomb, also known as a Spell Card or spiritual attack (presuming you have bombs left)
- C activates trance mode when the gauge is full.
- Shift slows the character's movement, and changes the nature of the character's shot; it generally makes your attacks more focused.
- Esc pauses the game and brings you to the in-game menu
- Ctrl fast-forwards through any dialogue
- Home or P produces a .bmp screenshot in the /snapshot directory. (Only works in 32-bit color mode.)
Ten Desires plays like a fairly typical vertically-scrolling danmaku shooting game, in which the player's character is always facing towards the top of the screen, shooting at anything that moves, avoiding and weaving between enemy bullets, and confronting difficult bosses at the end of a stage.
There are 4 levels of difficulty: Easy, Normal, Hard, and Lunatic. Each difficulty level features differences in the number of bullets fired by each enemy, rate of fire, variations in the bullets' pattern of movement, and the number and type of enemy Spell Cards used.
A character's "shot" is the player's primary method of attacking enemies. The shot's attack area and behavior varies depending on the character and attack type the player has chosen.
Point of Collection
Like previous Touhou games, there is a line most of the way up the screen called the point of collection. If you move your character at or above this line, all items on the screen will be drawn to your character. Unlike previous games, you don't need to have full power or focus to use the POC - it's always available.
A character's "bomb" is the player's limited-use method of getting out of difficult situations. A bomb's attack area, duration, and power varies depending on the character type and attack type the player has chosen, but it typically deals heavy damage to every enemy it touches, in addition to canceling out any bullets in the bomb's way. The player's character becomes invincible during and for a short time after the bomb's effect wears off. At the beginning of the game and any time your character revives, you will start off with 2 bombs. You can increase your bomb Stock by collecting 8 bomb pieces (represented by green divine spirits).
A player can use a bomb to negate a death by using the bomb within a very short time upon being hit by a bullet. Unlike previous games, this option is not always available to the player as being hit with your spiritual gauge charged will force you into trance mode immediately.
You start off the game with 3 lives. You can lose a life by getting "hit" by an enemy attack.
The hit box for your character is quite small in comparison to your on-screen sprite, approximately only 5 pixels by 5 pixels in size. If you hold Shift, a colored dot will appear, showing the hitbox precisely. If the hit box of your character's sprite comes into contact with the hit box of an enemy bullet, laser, or the enemy itself, then you have been hit.
In Ten Desires, the player's life stock is represented by stars. 8 life fragments are required to gain an additional life. This amount increases by 2 each time a life is gained. (Represented by pink/purple divine spirits).
When you lose a life, you also lose 1.00 Power points (0.07 are scattered for you to collect). Also, all the bullets on the screen are cleared, and you become invulnerable for a short period of time.
The main challenge and the main attraction. Each boss has multiple lives, which are represented by the circle surrounding the boss. Bosses usually alternate between attacking normally and attacking with Spell Cards, switching once with each health bar. A dash on the health bar indicate the start of a Spell Card attack when the boss' health is depleted that far.
Normal attacks are typically incrementally stronger versions of the boss character's basic attack. Spell Card attacks bedazzle the player with combinations of complex patterns that often involve the use of projectiles and obstacles crafted especially for use with that Spell Card. If the player manages to defeat a Spell Card attack without getting hit or using any bombs, a substantial score bonus is rewarded for the feat.
Each attack is accompanied by a timer. When time runs out, the boss will switch to their next attack pattern even if their health bar isn't empty. Waiting for a boss character's attack pattern to self-destruct may be enough to beat them, but mere survival won't earn the player any score bonuses.