Ganbare! Natsuki-San! is a puzzle platform game similar to the cult classic Umihara Kawase. The player controls the swimsuit-clad girl Natsuki, who is armed with only an extending claw with which to grapple onto objects. While latched onto an object, she can rotate around in any direction and jump off. The goal of each stage is to collect all the items scattered about, without falling victim to hazards such as spikes and water. There are 50 stages that can be freely played, as well as a full-run time attack mode, and the game tracks the player's best times and lowest jump count for each stage.