Kirby Designer Used This One Weird Trick To Save Memory Space

After launching his new YouTube channel in August 2022, longtime game developer Masahiro Sakurai has already reached the 100th posted video milestone. To celebrate, Sakurai shared some development secrets for another game he designed--and the first game he ever made--Kirby's Dream Land, including a novel way to create more characters using less memory space.

He first shows this off with two of Kirby's basic enemies, Waddle Dee and Waddle Doo. By using the same sprite for the duo's, uh, backside, he is able to create two distinct enemies using only 1.5x the memory. He also offers a quick way to remember which is which: The enemy with the one round eye has the name with the two round letters, "doo."

The video then shows the spiky enemy Gordo, where Sakurai reveals that Gordo is a single image that's mirrored vertically and flipped. By switching which side is flipped and which side is normal, Gordo can be made to look like it's shifting its spikes in and out as it moves across the screen.

Perhaps the most fascinating use of this technique comes from Whispy Woods, the tree that serves as the game's first boss. Here, Sakurai was able to create the tree's eyes and mouth by drawing a dark triangle, mirroring it horizontally, and then duplicating the resulting oval twice.

Other tricks of the trade revealed by Sakurai during the video include how he designed Kirby within the constraints of an 8x8 pixel grid, the staging and "set" of the game's first level Green Greens, and how the boundary rules for the game are the same as arguably Sakurai's most famous creation, Super Smash Bros.