U.N. Squadron is an Arcade Game produced by Capcom in 1989. This title is also known as Area 88 because it is based on the anime of the same name. This title was followed up by Carrier Air Wing, which unfortunately was not as good as its predecessor.
This is a shooter similar in gameplay to R-Type or Lifeforce. You play a pilot who has to go up against thousands of enemy planes. This may sound familiar since many games have been made from this premise. You get to select from one of three different pilots before your mission begins. This game scrolls horizontally, and all the levels move from left to right. You should be able to jump right in and play this one, as it is so similar to so many previous titles. One major difference between this game and other shoot-em-ups is that the game allows you to purchase powerups in between levels (all sorts of nifty attacks are available). The game has nice little cut-scenes in between each level, where you get to learn little tidbits about your pilots, and of course one of them is a girl (there is always a girl in anime games). The graphics are very nice, and hold up well even today.
One thing that must be noted it this, U.N. Squadron is a hard game. It may seem easy when you are at home playing it with MAME.But go play a real machine, with real quarters. Then you will realize how often you are actually putting in another quarter.
This game is Jamma compatible, and was sold as a conversion kit only (or in generic cabinets with the kit installed), there were no dedicated cabinets made. This game runs on the Capcom CPS hardware, just like Street Fighter 2, and many other titles from that era. Like many Capcom games, U.N. Squadron has a lovely little suicide chip on the mainboard. This can be bypassed with soldering, headaches, and a few new chips.
This game is emulated by 2 emulators, Callus and MAME. I recommend using Callus for slower computers, but any newer computers should be able to just use the MAME version instead. Or you can play the Super Nintendo version, which is a decent translation of the original.