Wakasagihime's Ocean Expedition

Wakasagihime gets to explore the ocean! Dive for crabs and other treasure to earn money, and buy upgrades to help you dive for longer. Yukari wants Wakasagihime to bring her horseshoe crabs — just what is the infamous gap-youkai planning to do with all those crabs? A game inspired by Ecco the Dolphin and Wakasagihime Speed Swimming (the only other Touhou fan-game inspired by Ecco, to my knowledge)…