The game can be played using either a keyboard or a controller.
Keyboard controls are as follows:
- The Arrow Keys are used for movement
- Z will fire shots; autofire if held down
- X activates the shield and keeps it active if held down
- Shift slows the movement of the ship, without changing the shot
- Esc pauses the game and pops up a menu that allows you to resume, restart or quit the game; during a replay, ends the replay
- Ctrl fast-forwards through any dialogue
- Space fast-forwards through a replay
The game consists of three stages played in order, as well as a separate Extra Stage, similarly to Touhou. There are no difficulty levels for the main game, nor is there any rank system. The main game allows you to use continues when you lose all your lives, while the Extra Stage does not. Unlike most games of its genre, Samidare has no bombs. The second button instead activates your shield.
The shot is the main, and only, method for the ship to attack enemies. It can power up by means of collecting items; it will power up at 8, 16, 32, 48, 64, 80 and 96 items, at which point it reaches its maximum power. The shot is the same across the main game and the Extra Stage, even though the ship colors and characters controlling the ships are different. A rain-like sound effect is played whenever one of your shots hits a target (either an enemy or a wall). At higher power levels, shots that fire at angles to the left and right sides are added to the main forward shot, making the shot slightly stronger at point blank range.
The shield is the defining feature of the game. It cancels out any enemy bullets within its radius and protects the ship from damage by collision. The shield may be held for about five consecutive seconds before running out of energy and dissipating. When the shield's energy falls below 25% or lower, it turns from blue to red. The amount of energy remaining is indicated by the shield meter, which is displayed both in the bottom-left-hand corner of the screen and again behind the ship.
One second after the shield is released, its energy begins to recharge. It takes about eight seconds for an empty shield meter to refill completely.
Whenever the shield cancels enemy bullets, the player's shot becomes wider, stronger, and bright orange. This more powerful shot is called the hyper. The hyper lasts for a length of time determined by the number of bullets cancelled by the shield, as indicated by a hyper meter that appears just below the shield meter behind the ship for as long as the hyper is active.
As a secondary effect, an active shield enlarges your hitbox for the purpose of collecting items.
The number of lives may be set in the options menu to any value from 1 to 5, with 5 being default. This applies to both the main game and the Extra Stage. No extra lives are ever awarded during play. If you lose a life, your shield energy will be set to 50% and begin recharging immediately.
In the main game, if you run out of lives, a countdown begins and you are given the option to continue play from where you died. This may be done up to three times. If you do not wish to continue, press Escape to end the countdown immediately. If you do choose to continue, you will resume play from the point where you died, with as many lives as you started the game with, and with 1 point added to your score. It is not possible to determine whether someone has continued based on score, as certain other events may also award points in non-multiples of 10.
Each boss uses a specific number of patterns in a set order, each with a different number of seconds on the timer. The health bar of the boss is shown at the top of the screen, with a smaller health bar, depicting the health of only the current pattern rather than all boss patterns added up together, shown right below it. When destroyed, the boss will award a fixed number of points and, if it happens to be a stage boss and not a midboss, the current stage will be finished, causing the clear bonus to be awarded, after which the game moves on to the next stage, if any.
- High score and current score
- Lives remaining
- Number of items collected
- Current shot power level
- The progress bar indicates the progress to the next level
- Current date, current time, time the game has been running for, and total play time.
- Boss health
- Only when boss is on screen
- Player ship and shield
- Shield energy
- Game window
Destroying enemies gives a small number of points by default, while destroying bosses gives a relatively large number of points. Notably, the score gain from destroying enemies in the Extra Stage is much higher than in the main game. Points are also awarded for hitting enemies or walls with your shot, at a rate of 100 points per shot, or 300 points per shot if using the hyper. Using the shield to cancel enemy bullets does not award any points.
Enemies drop items when destroyed, which can be picked up for points. They give more points the higher your power is, while also giving more points the more items you collected consecutively without dropping any. At below maximum power, the position of your ship on the screen matters, while at maximum power it does not. The maximum value of an item is 5,120 below maximum power, which applies when the item is collected high up on the screen. At lower positions, the item value ranges from 20 to 2,560 depending on the height. At maximum power, the points gained from picking up an item ranges from 10,400 to a maximum value of 25,600 depending on your consecutive collection. If an enemy is destroyed at point blank range, the item dropped by it is collected automatically.
In the Extra Stage, the bakebake in the third part of the stage have a special property, namely that they cancel all their bullets into items when destroyed, which is especially important for scoring that particular section.
If an enemy or boss is destroyed using the hyper, the score awarded by it will be multiplied by 16, as indicated by yellow 'x16' text shown on screen at the location of the enemy being destroyed. This is the single most important scoring mechanic in the game. It is especially important on bosses; the points awarded from getting the multiplier on bosses in the Extra Stage are several millions.
List of points gained from destroying the bosses of the game with the x16 multiplier:
Stage 1 midboss: 256,000 Sylphid: 64,000 Anareta: 64,000 SMD-00x: 600,000 Extra midboss: 16,000,000 Mai: 10,000,000 Gates: 24,000,000 VIVIT: 28,800,000
In the main game, the Stage 2 midboss does not award any points from being destroyed, as its last pattern does not have a health bar and the midboss simply self-destructs once the timer hits 0.
Boss patterns award a time bonus when their health bar is emptied, which is proportional to the amount of time left on the timer when the pattern ended. This is one of the two main scoring methods on boss battles, the other being the x16 multiplier. For most boss patterns in the game, it is worthwhile to finish them as fast as you can; there are however a few patterns that involve the boss firing missiles, during which it can be worth more points to delay finishing off the pattern in order to shoot down the missiles using your hyper to get x16 multipliers on them.
At the end of every stage, a clear bonus is awarded, which is calculated as follows:
Stage x 1,000,000 (stage number, Extra = 4) Items x 1,000
If the player never died during the stage, a No Miss Bonus equal to 1,000,000 points is awarded in addition to the two parts of the clear bonus.
To unlock the Extra Stage of the game, one has to clear the main game without using any continues.
- On the second pattern of the Stage 1 boss Sylphid, a time bonus of 28,800 is awarded if it is timed out, even though no other pattern awards a time bonus if timed out.
- Ending the last pattern with wings on the Stage 3 boss SMD-00x at the same time as killing either wing may cause the final pattern to glitch out and also fire blue and orange lines of bullets from previous attacks. If the boss is killed while this is happening, the game will crash and the current credit, as well as any play time gained during the session, will be lost.
- Occasionally, the game might crash after saving a replay. The replay will have been saved correctly, but if a new high score was attained, it will not have overwritten the previous one.