28天半衰期 — cheap CD keys, compare prices
Is it worth buying?
- The price is at or near its all-time low — a good time to buy.
Estimate based on public reviews (Metacritic/Steam) and price history — the final call is yours.
About the game
28 (28天半衰期) follows six exchange students from other dimensions whose lives get upended after an ammonia leak. The protagonist, a survival-minded biology student, has only four weeks left to land a girlfriend, or else marry the cow-throwing friend he's known since childhood. It turns his final semester into something far messier than planned. The game was developed and published by Singularity Studio in 2026.
Best price today
€3.63
all-time low: official €3.63 near low
The cheapest 28天半衰期 key right now costs €3.63 at Steam. The lowest price we have recorded for this game: €3.63.
The average low over the past 3 months was €4.32.
Prices as of
Steam best price Official store
No offers match these filters — try widening them.
Listed seller price shown — payment fees may vary by method.
Lowest — official stores
€3.63
Oct 2026
Price history
last 65 daysMonthly price lows
| Month | Lowest official | Lowest keyshop |
|---|---|---|
| Oct 2026 | €3.63 | — |
| Sept 2026 | €5.19 | — |
| Aug 2026 | €4.15 | — |
Lowest in-stock price per month from our price history; the current month is the low so far.
How to activate your key
- Steam key — open the Steam client → Games → Activate a Product on Steam → enter the key. Stores with this activation: Steam
Price alert Catch alert Price alert
Confirm in our Telegram bot — no account, no spam.
All-time low so far: €3.63
System requirements
| Minimum | Recommended | |
|---|---|---|
| OS | Windows 7 / 8 / 10 / 11（64-bit） | Windows 10 / 11（64-bit） |
| Processor | Intel Core 2 Duo 2.0 GHz or equivalent AMD CPU | Intel Core i3 or better |
| Memory | 2048 MB RAM | 4096 MB RAM |
| Graphics | OpenGL 2.0 / DirectX 11 compatible GPU with 512 MB VRAM | Dedicated GPU with OpenGL 3.0 support and 1 GB VRAM |
| DirectX | Version 11 | Version 11 |
Similar games
About this game — FAQ
Can 28天半衰期 be played single-player?
Yes, 28天半衰期 is a single-player game.
What languages does 28天半衰期 support?
28天半衰期 is available in: Simplified Chinese.
Does 28天半衰期 use Steam Cloud saves?
Yes, 28天半衰期 uses Steam Cloud, so your saves sync across devices.
FAQ
Where is the cheapest place to buy a 28天半衰期 key?
The cheapest 28天半衰期 key is currently sold by Steam for €3.63. The lowest price we have ever recorded for this game: €3.63.
How much does 28天半衰期 cost?
28天半衰期 currently costs from €3.63 — the cheapest offer across the stores we track.
Is Steam an official store or a keyshop?
Steam is an official store — keys come directly from the publisher or an authorized distributor.
Are keys from these stores legal?
Buying is legal — keys come from the grey market, so a small deactivation risk exists. So before paying, check the seller's buyer protection.
Which key region should I pick?
Global activates everywhere. Regional keys (Europe, North America, RU-CIS) only work on accounts from that region — use the Region filter to match your account.
What is an activation platform?
The service where the key activates — Steam, GOG, Epic or the publisher's platform. A key for one platform won't work on another, hence the separate filter.
What's the difference between editions?
Standard is the base game; Deluxe usually adds an expansion or bonus content. The edition filter shows exactly that variant, with no mixed prices.