Suikutsu Monogatari
Suikutsu Monogatari is a Cave Story themed take on Suika Game by Yobonnie with music by Retrodigital. You drop either a Critter, Balrog, or Igor onto the field, and anything that matches will combine into something larger when they touch.
Two critters become Balrog, two Balrogs become Igor, two Igors become Ironhead, two Ironheads become the Monster X cat, two Monster X cats become Omega, two Omegas become Balfrog, two Balfrogs become Heavy Press, two Heavy Presses become Undead Core, and two Undead Cores become Ballos.