Jiffy

Double-tap the jump button and Jiffy turns from platformer into shooter mid-air, sending a shot at whatever's chasing you. That single mechanic is the whole game: jump to clear obstacles, jump again to fire, and figure out which one you need in the next half-second.

The pixel-art world doesn't slow down to let you think. Blocks shatter when you hit them right, enemies pour in from odd angles, and over 25 levels the pattern keeps shifting just enough to keep you honest. Bosses show up when you're getting comfortable, which is exactly the point.

When the levels are done, endless and battle modes keep the reflexes warm. It's built for fast-paced games fans who like their reactions tested, and it runs free in the browser on desktop, Android and iPhone - no download standing between you and the next jump.

Reach the end of each level while clearing obstacles and taking down enemies along the way.

On desktop, move with WASD or the arrow keys and jump with Spacebar. Tap Spacebar more than once to shoot instead of just jumping. On mobile, use the on-screen move and jump buttons, and tap the jump button more than once to fire.

Time your jumps before you worry about shooting - most early deaths come from mistimed leaps, not missed shots. Once movement feels automatic, start double-tapping through enemy clusters instead of dodging around them.