power-up n.

Pick up the bonus objects in the room for bonus points! Power-up crown will appear after all the bonus objects are picked up[.]

Some wall sections contain power-up capsules. [...] Power-up capsules are effective until the player is shot down, the round cleared, or until another capsule is picked up.

Karnov from Data East is apparently a little like Ghosts ’n’ Goblins and Super Mario Bros. It’s a horizontal scrolling game with you as the hero Karnov—a fattish balding creature, single handedly fighting off the forces of evil. [...] Lots of action, ladders to climb up and down, power-ups to collect and bombs to throw.

[in the game Gianni Sisters] You are awarded a bonus depending on the amount of time left at the end of a wave, it is sometimes better to get more power ups and bonus than to go for the time score. If you are killed mid-wave you lose all bonus and powerups and have to start in that wave again (not always at the beinning [sic] of the wave).

[in the game Contra] Destroying a flying capsule or pillbox sensor provides an opportunity to acquire more power. When one of these objects explodes, a ‘power[-]up’ Falcon symbol appears. If it is captured, one of seven special weapons replaces a standard gun.

In Zillion™, when in the main elevator shaft, go left at the first tunnel until you get to the end. Then start shooting at the wall and a new room will appear. Then go up the elevator, go left, blow up the warrior, lie down and start shooting at the wall. A Power-Up will appear!

On screen, The Lizanator was fighting an army of wookie-men, sword in one hand, laser-blaster in the other, rocket-jumping, spinning, strafing, making impossible kills and long shots, diving for power-ups and ruthlessly running her enemies to ground.

I’d seized upon this idea a few years earlier when I coded my first Atari 2600 game (a gunter rite of passage, like a Jedi building his first lightsaber). It was a Pitfall rip-off called The Stacks where you had to navigate through a vertical maze of trailers, collecting junk computers, snagging food-voucher power-ups, and avoiding meth addicts and pedophiles on your way to school. My game was a lot more fun than the real thing.

Depending on the game, you may opt for microtransactions—the term for in-game purchases in which players can pay for online goods with real money, sometimes as little as 99 cents—to unlock new levels, items and power-ups or character costumes.