Reaction Challenge — 8 Reflex Challenges
From catching the moment the screen turns green to hold back, timing, target, cup stacking, color, rapid tapping and press & hold — eight modes to test your reflexes, with a daily challenge and 2–4 player battles on one phone
한국어로 읽기 반응속도 챌린지 — 8가지 순발력 챌린지
Info
Reaction Challenge is a reflex game with eight challenge modes — reaction, hold back, timing, target, cup stack, color, 10-second tap and press & hold. A new Today’s Challenge every day gives everyone the same puzzle, and every mode supports 2–4 players racing on one phone. Works offline, no sign-up.
October 2026 Update — Eight Challenge Modes
It started as a single test: wait for green, then tap. With this update there are eight ways to measure your reflexes. Pick a mode on the home screen and start.
| Mode | How it works | Score |
|---|---|---|
| ⚡ Reaction | Tap the instant it turns green | 5-round average reaction time |
| 🚦 Hold Back | Tap on green, hold back on red, blue or yellow | Average reaction time + trap penalties |
| ⏱️ Timing | Stop at the target time. The clock vanishes after 1.5 s | 5-round average error |
| 🎯 Target | Tap when the bouncing ball hits the center, 5 s per shot | 5-shot total + combo bonus |
| 🥤 Cup Stack | Stack exactly the target number of cups, then press Done | Time per cup (+1 s for each cup off) |
| 🌈 Color | Tap the moment the shifting color matches the target | Average match |
| 👆 10s Tap | Tap as many times as you can in 10 seconds | Taps |
| 📏 Press & Hold | Let go of the rising bar right on the target line | 5-round average error |
A different ball for every shot
All five shots are different: a basic ball, a wobbly ball that bounces off at sharp angles, a curve ball that bends in flight, a stop-start ball that freezes now and then, and finally a target that shrinks as time runs out. The ball’s angle and speed change a little on every bounce, so you can’t read its path ahead of time. You still always get chances as it crosses the center.
Hit the 10-point bullseye in a row and you earn a combo bonus: +5 for a 2 combo, +10 for 3, +15 for 4 and +20 for 5. Five bullseyes in a row is a perfect 100.
Press & Hold punishes holding on
Once the bar fills to the top, it drops back down. Hold until it empties and your release counts as 0%. Even when the target line sits near the top, simply holding the whole way won’t score.
Today’s Challenge
The card at the top of the home screen switches to a different mode every day, and everyone gets the same puzzle that day — the same target time in Timing, the same ball path in Target. Your best score for the day stays on the card, and you can try as many times as you like.
2–4 players in every mode
Split the screen into two to four zones and compete at the same time on one phone. Every zone gets the same puzzle, and the top zones rotate 180° so players can sit face to face. When the round ends, each zone shows its rank.
Every mode has six grades, and the result screen tells you how far you are from the next one. Records are kept per mode as a TOP 10, plus today, this week and this month.
When the Screen Turns Green, Tap
This is the original reaction mode. You watch a red screen and wait. The moment it changes is different every time. Tap as it turns green and the milliseconds in between become your time. Five rounds are averaged into your score.
Tapping early does not count. If your hand goes before the green, you get Too fast! and that round starts over. The longer the wait runs, the harder it is to hold still, and the game shows you exactly that habit.
- ⚡ Five-round average — one lucky tap will not carry you
- 🏆 Six grades — Pro Gamer, Cheetah, Eagle Eye, Cat, Ordinary Human, Relaxed Sloth
- 👥 Up to four players at once — share one phone; the top zones rotate 180° so people can sit face to face
- ⏱️ Early tap costs +100ms — in multiplayer it is a penalty rather than a disqualification
- 🏅 TOP 10 records — a new best shows you where it landed
- 📣 Share your score — send the result straight to a friend
It works fully offline with no sign-up or login.
Gameplay Video
Download
- Google Play: https://play.google.com/store/apps/details?id=com.fadongkwon.reaction (opens in a new tab)
- Apps in Toss: https://fadongkwon.com/toss/reaction/ (opens in a new tab) — open it on your phone and it connects straight into the Toss app.
Released Alongside
Memory Cards went out the same day. These two were where I first tried building in web technology and publishing to Google Play and Apps in Toss at the same time.
After these, mini games started shipping in batches. That story is in Shipping Six Mini Games at Once.
I post updates here and on Instagram (@fadongkwon.soft) (opens in a new tab).