Clockwork Aquario

Clockwork Aquario is an action-platform game reminiscent of Super Mario Bros. and Wonder Boy III: Monster Lair, where players assume the role of Huck Rondo, Elle Moon or the robot Gush through five stages in order to stop Dr. Hangyo with his plan to take over the world. Players attack by stomping or slapping to grab and throw enemies out across multiple directions, headbutt enemies thrown at characters, as well as catching enemies thrown by other players.

In addition, a player can pick up another player and throw them against enemies. Players also have the ability to turn invincible against enemies for a brief period before the character's invincibility gauge is depleted, which can be replenished by picking up items.

Clockwork Aquario was created in 1992 at Westone. It was intended to be their final arcade game, and most of the staff were previously involved with several entries in the Wonder Boy/Monster World series. Clockwork Aquario was designed to push the hardware limits of the Sega System 18 board. Ryuichi Nishizawa served as designer alongside programmer Takanori Kurihara, artist Mina Morioka and composer Shinichi Sakamoto.

Both Nishizawa and Sakamoto recounted the project's development process and history through various publications, stating that the project was created over the course of two years and intended to resemble Wonder Boy III: Monster Lair but focusing on co-op play before the team added a third player. However, the team reverted to a two-player format at one point during development. Nishizawa stated that the game was coded in Assembler language and recalled that the team used in-circuit emulation for debugging. Nishizawa claimed that the System 18 was a complex and difficult board to work with, due to programmers having to control two graphical functions with one MPU.

According to review aggregator site Metacritic, Clockwork Aquario received "mixed or average" reviews on both PS4 and Switch. Famitsu's four reviewers found it to be a simple side-scrolling action game, commending its simple but deep combo-chaining system, colorful visuals reminiscent of the Mega Drive era, detailed backgrounds, controls and overall presentation, but they felt mixed in regards to the grab and throw mechanic. HobbyConsolas' Daniel Quesada praised the game's steampunk-esque design, Shinichi Sakamoto's soundtrack, dynamic co-op multiplayer and presentation but criticized its short length, unbalanced difficulty curve, repetitive and low quality character voices and overall visibility due to the colorful visuals. Reviewing the PS4 version,

J. Maciejewski found its pick-up-and-throw gameplay mechanic to be unconventional and gave positive remarks to the visuals, cartoon-style artwork, energetic music, frantic multiplayer and presentation. However, Maciejewski criticized the title for its short length and unfair surprise enemy attacks, while also noting that each character using the same playstyle felt tedious. Nintendo Life's Kerry Brunskill gave positive commentary to the pixel art, creative stages and multiplayer, but noted its short length, certain aspects of the presentation and extra modes for being minor variations of the main game.