Development Hell: Not the series, but fan subs were another matter entirely. This series remained practically unknown to the English speaking anime fandom for YEARS. Some years ago, four episodes were subbed but the series was dropped and left in limbo. Luckily, a fansub group named Silver Zero Subs began subbing it in 2010 and continued on for four whole years, and as of today, it's fully subbed.
Ear Worm: The OP will stay in your head for decades.