ASTRA is a reflex game you play with a single input: a tap. The rules take about a minute to learn,
but the ring speeds up with every successful tap and the gate you are aiming at keeps getting narrower.
This page walks through the screen, the timing windows, and how the three difficulties differ.
1. One input, nothing else
There are no buttons. Tap anywhere on the screen on a phone, or click or press the space bar on a computer.
The game is built to be playable one-handed, standing up, on a crowded train.
2. Reading the screen
There is a large circle (the ring) in the middle of the screen, and two things live on it.
The dot — a small point that travels around the ring without stopping. This is your needle.
The gate — a glowing arc somewhere on the ring. This is your target.
The dot moves at a fixed speed regardless of what you do. The gate does not move. Its position changes every
time
and it is always placed a little ahead of where the dot currently is.
3. HIT and PERFECT
Tap while the dot is inside the gate and you score a HIT. Your combo goes up by one and points
are added.
Tap within the central 30% of the gate and you get a PERFECT, which
doubles the points from that tap. The flash, the sound and the haptic feedback all change,
so before long you can feel a PERFECT without looking for it.
Tip: Chasing PERFECTs also means missing more often. Early taps are worth very little because your combo
is small,
so it usually pays to bank safe HITs first and start reaching for PERFECTs once the combo has grown.
4. How a run ends
There are exactly two ways to end a run. Either way, a star is born from the score you reached.
You tapped outside the gate — too early or too late, the run ends immediately.
You let the gate pass untapped — there is no grace period. The moment the dot clears the
gate, the run is over.
Not tapping is never an option. Every gate has to be answered.
5. It gets harder as you go
Every successful tap changes the board:
The ring speeds up by a fixed amount per difficulty, capping at 7.5 radians per second
(about 1.2 rotations per second).
The gate narrows by a fixed ratio, down to a floor set by the difficulty.
The spin can reverse — once your combo reaches 5, each tap has roughly a 22% chance of
flipping the direction.
Because both the speed and the gate width have limits, every run eventually reaches a state that stops getting
harder.
From there it is purely about reading reversals and holding your concentration.
6. The three difficulties
Pick Easy, Normal or Hard on the title screen. Harder settings carry a higher score multiplier,
so the same combo produces a very different final score.
Property
Easy
Normal
Hard
Starting spin speed
1.4
1.8
2.4
Acceleration per hit
+0.09
+0.12
+0.16
Starting gate width(each side of center)
0.55
0.42
0.32
Narrowing per hit
×0.955
×0.94
×0.93
Minimum gate width
0.18
0.13
0.10
Score multiplier
0.8×
1.0×
1.3×
Speeds and widths are in radians (per second / angle).
See Scoring for how the multiplier actually reaches your score.
7. Your stars are permanent
Every run produces one star, added to your galaxy forever — including runs that ended badly.
A low score makes a small, dim star; a high score makes a large, bright one. Colour, size and rarity all come
from your score and combo. See Stars & Rarity for the details.
8. Where you can play
It runs in the browser. No install, no sign-up, playable the moment it loads. On a phone, use your browser's
"Add to Home Screen" to launch it full screen like an app and play with no connection at all
(records are kept on the device).
Creating an account stores your records in the cloud so your galaxy survives a new phone.
See the FAQ for more.