Mr. Driller Ace: Fushigi na Pacteria is a Game Boy Advance game in the Mr. Driller series, only released in Japan. In classic mode, the player must dig down stages by destroying colored formations. when a formation is destroyed, any formations above it will fall down. This will crush the player, so they must move to avoid falling formations. If a formation falls onto another formation of the same color, the two will merge, making a bigger piece. Some blocks can't be broken, forcing the player to work around them. The player's air supply also runs out over time, so the level must be completed before it is completely depleted. Extra oxygen tanks can be collected.
In the new mode, some changes are made to gameplay. In this mode, the air supply is depleted by 1% when the player destroys a block formation. If the player is crushed, 20% is lost. Items called Dristones can also be found. The effects of Dristones vary. They can change the blocks' colors, destroy them, are refill the player's air supply. There are also new creatured called Pacteria, which are like virtual pets. Items found in the underground can be given to the Pacteria so they can change color and form.
There is also a race game, where the player chooses a driller and races the others to the bottom of the course.