Defend the Dragon Palace!

Defend the Dragon Palace! is a defence game set beneath the sea. The player’s only direct action is digging into the seabed. Depending on which type of soil is excavated, different sea beasts emerge: nutrient-rich earth produces kelp and urchins, while mana-soaked earth produces sea bunnies and mermaids. There are eight species in total, including Kelp, Urchin, Octopus, Sea Firefly, Sea Bunny, Mermaid, Umibozu and Skeleton, and they form a single food chain. Kelp spreads, urchins graze on it and octopuses hunt the urchins. Creatures cannot be commanded; they move, feed and breed independently, and the resulting ecosystem acts as the defence for the Dragon Palace.

The layout of the dug tunnels determines the strategy, for example funnelling enemies into narrow corridors or opening wide chambers so creatures can surround them. Attackers include fishermen, harpooners, monks, armoured warriors and a turtle girl, each with a preferred tactic and a weakness. Defeated divers leave graves, which can be dug up to raise skeletons that fight for the player. Princess Skills, attributed to Otohime, the ruler of the Dragon Palace, are bought with coins earned during play from a shop on the title screen. There are eight skills with three levels each, one of which can be equipped at a time. Examples include healing beasts, levelling the dungeon with a quake, or digging several tiles in one strike.

The game contains eight stages estimated at roughly two to four hours, a higher difficulty mode unlocked after completion, two tutorials covering basics and advanced play, and Banquet Hall, a sandbox mode for digging and growing an ecosystem without pressure. It also includes a sea beast encyclopedia, a diver encyclopedia and an ecosystem chart. Full controller support is provided, with menus, encyclopedias and the shop navigable by pad alone, and controls are rebindable for mouse, keyboard and gamepad. Japanese and English languages are supported.