The game was intended to release much earlier. Argonaut started to work on the game in 1988 (first with no working title, later the game was named Hawk
), they even started a six part development diary in the UK magazine The Games Machine
in 1989 (issues #15, #16, #18, #19 and #20), all claiming a near release. Some more times the game was announced as nearly completed in the next year, but the final release was delayed until 1991, for which the game was renamed to the release title Birds of Prey
As the Devpac assembler, which was used at Argonaut, turned out to be too slow for such a big project, taking 15-20 Minutes for creating the game from code, Argonaut was looking for a better development tool. They didn't moved to a PC cross-assembling platform which many other companies did at the time, but developed their own assembler "ArgAsm" ("Argonaut Assembler"). It turns out to be up to 10 times faster then Devpac. This side product of the game development was then sold as a commercial development tool.
Even before the release of the game, publisher Electronic Arts asked Argonaut to develop a sequel, which the development company rejected, as they preferred to develop for the Nintendo consoles Gameboy and Super Famicom. Therefore a sequel was never in development.