Hyper Dyne Side Arms, or just Side Arms, is a horizontal shoot 'em up from Capcom. Up to two players can take advantage of the Mobilsuit, a mecha that can transform into a spaceship and has considerable firepower, to take on an alien invasion force. The Mobilsuits can combine to form a much stronger mech: in two-player mode, this combines both players' Mobilsuits and confers control of the eight-way guns to one player and navigating the combined mecha around the screen to the other.
The game was originally released in the Arcades in 1986. It saw a TurboGrafx-16/PC Engine release in 1989; the US version was published by Radiance. It also saw multiple home computer versions in Europe, developed by Probe Software, including a 1987 PC release with CGA graphics and without music. The Arcade version was later added to the Capcom Classics Collection Remixed for PSP and Capcom Classics Collection Vol. 2 for PS2 and XBox.