Gradius/Trivia

Bad Export for You: The NES Life Force only allows two options per ship (instead of three like its FC counterpart) and lacks the multiple endings from the FC Salamander; its sole ending is a static shot of the Konami logo while the ending theme plays.
Follow the Leader: A great many shooters followed the Gradius powerup system, sometimes expanding it into a between-levels "shop" where points could be exchanged for powerups, other times using it verbatim.
Keep Circulating the Tapes: The mainline games are fairly good about this, each game from I through IV having had about 1-3 Arcade Perfect Ports, but the Solar Assault Gradius sub-series never saw a console release (you may be lucky to find one at Chuck-e-Cheese's).
No Export for You: Much of the series. In fact, in a world where ~~the U.S.~~ North America gets priority over Europe when it comes to video game releases, the opposite applies for not only this series, but the Affectionate Parody, Parodius, as well.
Sequel First: Gradius II was released in 1988 in Japan and Europe, but not in North America, where it was officially unreleased until its appearance on Gradius Collection in 2006. Gaiden is a milder example; IV and Galaxies came after it and were released here before Collection (which included Gaiden as well).
What Could Have Been: The canceled racing game Vic Viper.
Wiki Rule: Yes, it has one.