Core ReactorAndroid · Idle strategy · Free
Your phone’s battery is the reactor.
Charge it, use it, forget it. An underground base keeps producing the whole time. Come back to a report, spend three minutes on a puzzle, get on with your day.
Free · No account · No Game Over
- 10
- Power for every 1% of battery. That is the whole exchange rate.
- ×1.25
- bonus while your battery sits in the 20–80% Health Zone.
- 0
- timers or fail states in Contract puzzles. Undo as often as you like.
- 8 h
- of offline production by default, extendable in the Lab.
01 · Daily Rhythm
Three things your phone already does.
Core Reactor does not ask for anything new. It reads what the phone is doing anyway - plugged in, screen on, screen off - and turns it into production. You are not controlling the game with the phone; the phone sets its rhythm.
Accumulation
Plugged in and charging
The Reactor fills the Capacitor. The biggest source of Power: 10 for every 1% of battery gained.
Draw
Unplugged, screen on
You are playing, scrolling or just looking at the phone. Moderate production, and the Silicon fabs turn Power into material for upgrades.
Idle
Unplugged, screen off
The phone lies on a desk. Slow, steady production while the base cools. You see the result in the Return Report, not live.
Health Zone. Battery between 20% and 80% pays ×1.25. From 80% to 100% it pays ×0.6. The game quietly pays you to stop topping off to 100%.
Heat is a brake, not a goal. Under 35 °C gives +10%. Over 40 °C throttles production by 20% and locks Overclock. Heating the phone is never rewarded. Full rules and numbers →
A stable base pays a little extra. From Era 2 the Heat layer is a game value, not your phone’s temperature. When the Cooler removes at least 60% of the heat your nodes make, the base is stable and gives +5% Power. If it does not keep up, production is simply normal.
Small bonuses, no penalties. From Era 2 the base also pays extra for a night with the screen off, battery saver, Do Not Disturb, headphones at a low volume and a minute in daylight. Skip any of them and production stays normal. What the game reads →
02 · The loop
Come back to a report, not a chore.
Read the timeline
See how long the base ran and how much of that was Accumulation, Draw and Idle.
Collect Power, Silicon and Code
One tap and it is yours. The base keeps producing for hours while you are away, so there is always something waiting.
Handle an Anomaly
Now and then the reactor reports an irregularity. Stabilize for a safe gain or Risk it for a bigger one. There is no penalty either way, only a different payout.
Pick the next upgrade
Upgrade the Reactor, Capacitor, FAB‑SI or Cooler. Builds run on timers you can leave or shorten.
A session is 30–90 seconds. The reason to open it again is the next report.
03 · Contracts
A puzzle you can’t lose.
Contracts are short placement puzzles on a small board. No clock, no lives, unlimited undo. You get stars for how well you solve it, and stars make the whole base more efficient.
Place Factories, Coolers and Generators
A Factory makes 2 Power, plus 2 per adjacent Cooler, plus 1 per adjacent Generator. Neighbours are up, down, left, right. No diagonals.
Watch the heat
Generators add 3 heat, Coolers remove 2, and two Factories side by side overheat and lose Power. So you cannot just pile everything together.
Earn up to three stars
★ reach the production target. ★★ also use few modules. ★★★ also keep heat low and hit the best possible production.
Come back for the Daily Contract
The same board for every player, with one reward per day.
Difficulty grows from rules, not board size. Boards go from 3×3 up to 6×6 and never zoom. Stars are earned by solving.
04 · Long game
Five Eras. Each adds one rule.
Eras are how the game stays interesting without making the board bigger and bigger. Every Era adds a mechanic you have to rethink your layouts around.
| Era | Name | Board | What it adds |
|---|---|---|---|
| 1 | Micro‑Shelter | 3×3 | The basics, the tutorial, the Return Report. |
| 2 | Clusters | 4×4 | The Heat layer with a small Stable Base bonus, blocked cells, irregular board shapes, Environmental Harmony bonuses. |
| 3 | Flux | 5×5 | Source cells, directional modules, Flux from your connection type (Quantum Isolation without a network: Code +50%). |
| 4 | Autonomy | 6×6 | Scripts (priority rules) and a heat limit. |
| 5 | Dyson | 6×6 | L‑shapes, weekly modifiers, asynchronous rankings. |
Reboot is prestige, not a wipe.
At 80% of an Era you can Reboot. It resets that Era’s base and gives you Blueprints (a permanent multiplier and unlocks) and Protocols. Your premium currency and purchases are kept. The first Reboot is meant to arrive after two to three weeks of normal play.
“Delete progress” in Settings is a different, separate action that erases everything, and asks twice.
The Lab spends Code on permanent upgrades.
Longer offline cap (12 h, then 24 h), auto-routing, extra Health Zone bonuses and more. Research runs on timers like builds.
05 · Calm by design
A game that stays out of your way.
No pressure, no pile of permissions, no hours of your day.
- No Game Over
- Nothing permanent is ever taken away. Ignore the game for a week and the worst that happens is a slower Idle rate.
- No account
- Install and play. Your progress and battery samples stay on the phone.
- Light on battery
- The game checks in about every 15 minutes. No always-on service and no permanent notification.
- Few permissions
- No usage access, no location, no contacts. Details in the privacy policy.
- Earned, not bought
- Power from charging and stars from Contracts come from playing.
06 · FAQ
Questions people ask first.
What is Core Reactor?
An idle strategy game for Android. You run an underground reactor base that produces Power, Silicon and Code while your phone does ordinary phone things. When you open the app you get a Return Report, and when you want to play, short Contract puzzles.
How can a game use my battery?
Through standard Android battery and network information: charge level, whether you are plugged in, battery temperature, and the connection type (Wi‑Fi, mobile or none). From Era 2 it also checks battery saver, Do Not Disturb, headphones and, while the base screen is open, the light sensor. It never reads traffic volume, apps you use, location, contacts or notifications.
Will it drain my battery or run in the background?
No always-on service. Samples are taken through Android’s WorkManager roughly every 15 minutes, plus when charging or connection changes while the app is open. There is no foreground service and no persistent notification.
Do I have to charge my phone to progress?
No. Charging is the strongest source of Power, but Draw (screen on, unplugged) and Idle (screen off) both produce too. Contracts, the Lab and upgrades progress regardless. If you cannot charge right now, Settings has a 60‑second Simulation Mode.
Why does it pay less above 80% battery?
That is the Health Zone. Between 20% and 80% Power is multiplied by ×1.25; from 80% to 100% it is ×0.6. It nudges you away from topping off to 100% every time, which is also gentler on lithium batteries. Heat works the same way: it is a brake, never a reward.
Can I cheat it by plugging in and out, or by heating the phone?
Not usefully. There is a daily cap on gains, a minimum plugged-in time before Accumulation counts, a 60‑second debounce on state changes, and throttling above 40 °C.
Is it free?
Yes, and you can complete it without paying. Power from charging and stars from Contracts are earned by playing and can’t be bought.
Are there ads?
Only optional ones you choose to watch for a bonus. There are none during a Contract puzzle.
Is there a Game Over?
No. Nothing you skip or fail permanently takes anything away. The worst outcome of ignoring the game for a week is a slow Idle rate.
Do I need an account or internet?
No account, ever. The base is simulated on your phone; internet is used only for things like ads, purchases and diagnostics, as listed in the privacy policy.
Is there an iPhone version?
Not yet. Core Reactor is Android-only for now, in English and Polish.
Plug it in and walk away.
Your first Return Report is waiting at the end of your next charge.
Scan to open on your phone