Room 1-3 (Mario vs. Donkey Kong: Minis March Again!)
From the Super Mario Wiki
The course features two mini toys.
The minis start on a platform on the left side of the stage. In order to reach the Goal Door, they must simply descend a level lower and head straight ahead. There is initially a set of Pink Blocks that blocks the path leading to some spikes on the left; however, the player is not required to use these blocks.
Mini Mario Card
The Mini Mario Card is on the right side of the course, across the cluster of Pink Block spaces. In order to reach and collect it, the Minis must be led there with Pink Blocks.