Densetsu no Starfy (GBC)
Densetsu no Starfy for the Game Boy, and later for the Game Boy Color was a tentative Starfy title which was eventually canceled. Any initial plans of releasing Densetsu no Starfy for the Game Boy Color were abandoned, in anticipation of the release of the Game Boy Advance (or 'AGB'; 'Advanced Game Boy' as it was called in its early development). In its replacement, Densetsu no Starfy was released for the Game Boy Advance on September 6, 2002.
History
Planning on this game began as early as 1995, for the original Game Boy when Nintendo producer Hitoshi Yamagami was asked by TOSE's producer, Yasuhiro Minamimoto to come up with some kind of 'floaty platformer'. [1] After six months of work on the game, Hitoshi thought of using a floating character to be pushed through a maze and initially designed a balloon lifting game until canceling it due to difficulties of having the balloon move where it was intended to. In Hitoshi and Yasuhiro's opinions, these difficulties would make the project 'uninteresting' and 'annoying', so a different approach was to be taken. [2]
Later, Hitoshi asked if they could take control of the floating character, rather than just moving it around. Hitoshi and Yasuhiro both decided that using a water based character would be a good idea, as long as that character fit the environment. Both a jellyfish and a starfish were initial considerations, and a starfish, was eventually chosen for this game. Development on this game continued through 1998 and as such, Nintendo encouraged TOSE to rework this game for the Game Boy Color. In 1999-2000, as the game was approaching its release for the Game Boy Color, it was again canceled and rebuilt for the Game Boy Advance which was only going to be released in two years and later became the final Densetsu no Starfy for the Game Boy Advance. Starfy was apparently going to be purely a starfish, until he was made to fall down from the sky, which started the community policy for TOSE to reply that Starfy is neither a star or a starfish when asked.
There are various differences between the Game Boy Color version and the final Game Boy Advance version still noticeable on Nintendo of Japan's page about the prototype. For example, the official logo and some of the character artwork and names of characters were changed.
Gallery
Old Man Lobber as he appeared in the canceled beta version of Densetsu no Starfy for the Gameboy Color. 
Moe as he appeared in the canceled beta version of Densetsu no Starfy for the Gameboy Color. 
Ootaruika as he appeared in the canceled beta version of Densetsu no Starfy for the Gameboy Color. 
A stage, which is probably a pre-cursor to Sea of Ice. 
A stage, which is probably a pre-cursor to Coral Reef. 
Another stage. 
A stage, which is probably a pre-cursor to S.S. Logwater.
