About Odd Arrow
Odd Arrow is a spot-the-difference game at speed. The screen shows a grid of yellow arrows. All but one point in the same direction. Tap the one that does not, and the next grid appears at once.
How it works
You start with a two by two grid, which is trivial. Every three correct answers, the grid gains a row and a column, until it reaches six by six with thirty-six arrows to check.
The odd arrow may be turned a quarter turn either way, or point in the opposite direction entirely. The shared direction changes with each grid too.
The clock runs for thirty seconds in total. A wrong tap does not end the game, but it knocks two seconds off, which is a heavy price.
Playing it well
Do not read the arrows one at a time. Soften your focus and look at the grid as a whole. A field of identical shapes forms a texture, and the one that breaks it tends to stand out without being searched for.
If nothing jumps out, scan in rows, left to right, as you would read. An orderly sweep is faster than letting your eyes dart around.
An arrow pointing the opposite way is the hardest kind to see, because it lies along the same line as its neighbours. If a quick look finds nothing, that is probably what you are hunting for. Look at the arrowheads.
Be sure before you tap. Two seconds is longer than it takes to check again.
Keep your hand near the middle of the grid so that no arrow is far away.
Twelve or more in thirty seconds means you have dealt with the larger grids quickly. As visual-search HTML5 games go, it is short and sharp.