Left or Right: Quick Sort — A 60-Second Reaction Game Where the Rule Keeps Changing

A card appears in the middle. Send it left or right by the current rule before time runs out, and watch out, the rule changes mid-game. 3 levels. Now on Google Play

Posted Nov 10, 2026

Left or Right: Quick Sort feature graphic

By Fadongkwon Soft

1 min read

Left or Right: Quick Sort — A 60-Second Reaction Game Where the Rule Keeps Changing

한국어로 읽기 좌우 분류 — 카드를 규칙대로 왼쪽·오른쪽으로 보내는 60초 순발력 게임

Info

Left or Right: Quick Sort — Send each card left or right by the rule. The rule changes while you play. Free to play on Google Play, with ads.

About the Game

A card appears in the middle. Send it left or right by the current rule, shown on both sides of the screen. You have 60 seconds, and the rule changes while you play. Your score is correct answers minus wrong ones. It is one of the brain games in FDK Brain Check, now also available as its own app on Google Play.

How to Play

Pick a level on the home screen and tap Start
The pictures on the two sides are the current rule. Send the card to the side that matches it
Tap the left half or the right half of the screen
When the “rule changed” alert appears, check both sides again
A wrong answer locks you for half a second and the card stays

Features

3 levels: Easy sorts by shape only. Normal swaps the sides every few cards. Hard switches between shape and color
The rule is drawn with pictures, so you can play without reading
Results show correct, wrong, best streak, accuracy and your grade
Top 10 for each level, plus bests for today, this week, this month and all time
3 free hearts every day. Each game uses one, and you can watch a short ad to get more
Works offline and plays in 9 languages

Free to play, with ads.