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.
No Export for You - A few games remain Japan-only. Gradius II (Famicom)note although Gradius II is available in some form in all three major gaming markets, the Famicom port deviates in stage design pretty strongly and Salamander 2 are two such examples.
Subverted for games that never got released in North America, but did in Europe, even though North America often gets priority over Europe with exports. The MSX-exclusive games (Salamander, Gradius 2 / Nemesis II, Gofer no Yabou Episode II / Nemesis III) come to mind.
The original Gradius II, released in 1988, remained out of the reach of the North American market until 2006 (as part of Gradius Collection)—that is, for eighteen years. Its PC Engine port followed suit in 2009 with a Virtual Console rerelease.
Port Overdosed: The first two Gradius arcade games and the original Salamander got ported to plenty of platforms in some form or another. Particularly in Japan, where the series got the Deluxe Packs on the PS and Saturn, as well as Collection series on PSP.
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).
The arcade version of V was in development, but the version was cancelled due to time constraints. This game could be the first mainline arcade Gradius game where Shadow Dancers can be destroyed instead of just avoiding.
V additionally would have had a feature where selecting the same slot on the powerup gauge multiple times will swap that weapon out with another one of the same category (e.g. replacing Missile with Spread Bomb or Laser with Ripple), but this was scrapped in favor of the traditional gauge select and unlockable gauge edit.