The original Dino Crisis was a widely popular survival horror (marketed as survival panic) game developed by Capcom and released on the original PlayStation in 1999. It was created by the same team that made the first Resident Evil game and contained many of the same tense elements but focused on more of an action feel.
A portable version of Dino Crisis was being developed for the Gameboy Color by British studio M4 Ltd, who had released Tasmanian Devil: Munching Madness and were due to release Jerry McGrath Supercross 2000. M4 stated that the game would not be complete until Q4 of 2000 but development had started early in the year, this was reported by IGN who spoke to the developers. M4 said that Dino Crisis for the GBC would be a top down adventure rather than how the original was, it would also be developed exclusively for the GBC by-passing any kind of black and white compatibility. Virgin interactive handled development for Capcom in the UK and so they were handling this game, there was no word on where it would be released. M4 Ltd version of Dino Crisis GBA was never released, but they developed top-down Resident Evil Gaiden, published by Capcom in 2001.
It seems that this unreleased version of Dino Crisis was used as a base to develop the released Resident Evil Gaiden. As we can read at NowGamer:
As I recall, we produced a very impressive demo for a GBC version of Dino Crisis. Resident Evil was already in development as an over-ambitious port from the PlayStation version. This was scrapped and Capcom asked us to do a bespoke game with our Dino Crisis engine.
Capcom had requested Virgin for a Dino Crisis demo, Virgin asked us to create it. It used the exploration mode and [similar] battle system as Gaiden would use.
It was playable. The dino sprites in exploration mode were large. I have entire backups of everything from M4, absolutely everything, but I’m in Brazil and the backups are in the UK.
This is not the only version of a GBC Dino Crisis that can be found on the web though, as on two separate Spanish websites Vandal and Dino Crisis Wiki the game was reported to be being developed by a different studio. This other cancelled game was said to be being developed by the now missing Fluid Studios another British developer who released games such as Top Gun: Firestorm (GB) and Army Men: Air Combat (GB and N64). This was also said to be being developed late 1999 early 2000, for the GBC.
There are a few more details for this version of the game though: it would not be a top down adventure but rather using static backgrounds and images accompanied by text sequences. Some presumed screenshots from Fluid Studios’ Dino Crisis seem to have been leaked online too, but we don’t know their source. These sites also report that the game was to be 7 maps with 100 rooms in total. There were to be four characters in the game Regina, Rick, Gail and Dr Kirk all who appeared in the original game on the PlayStation. Also it was said that there was going to be five types of dinosaur two unspecified with the others being the Tyrannosaurus Rex, Velociraptor and Pteranodon.
Update: While this article was being uploaded to the site I have been looking through documents that were released (you can find the design doc online) regarding the game that was in development by Fluid Studios. In this document it is revealed that what Fluid actually wanted to produce was a scaled down version of the original Dino Crisis, they wanted to keep all the original maps, plot-lines, dinosaurs and the look and feel of the original. This is quite a bold statement as the original was on the PlayStation 1 which is a more powerful system. Fluid were worried about the restrictive nature of the GBC especially in regards to the sprite size and how they would recreate the dinosaurs.
The story had a very brief background written about it, there was to be an undercover agent (Regina who had infiltrated the compound and was trying to capture Dr. Kirk and take him back to her government agency. Fluid also intended to have different game modes for this and it was said that they would have bonus missions if you had completed the game. This was said to contain three missions in which the player would have to kill a set amount of dinosaurs in a certain period of time.