I don't know about you, but I didn't know--until a few hours ago, at least--that more than two decades ago the folks at what was then known as Square made a game (for the MSX) based on the 1986 film Aliens.
I found out about it after watching said film (for, oh, the 20th or so time) last night--which prompted me to search the Interwebs for games based on James Cameron's blockbuster and its Ridley Scott-directed predecessor. That search led me to this destructoid.com article and this Wikipedia page--both of which mention Square's Contra-esque shoot 'em up.
Here's what it looks like in action:
Honestly, I don't think the game looks bad at all. It certainly puts to shame the Pac-Man-esque Alien title that appeared (five years earlier, admittedly) on the Atari 2600.
See also: 'Curiosity of the day: Sega's Mega Jet'