Grind Stormer, called V-Five or V-V (ヴイ・ファイヴ) in Japan, is a 1992 arcade shoot-'em-up developed by Toaplan. It was ported to the Sega Mega Drive in 1994 and released by Tengen exclusively in the US and Japan.
Though the two games have the same art, weapons, music, and enemy layout, their gameplay is slightly different:
V-Five: Gradius-style weapon upgrades, with / shooting and choosing a weapon
Grind Stormer: more conventional weapon upgrades, with / shooting and dropping a bomb
You can select which mode to play in the Options Menu by pressing at the title screen. Also during gameplay, you always have two auxiliary guns at your sides — and move them toward your front/rear. When at the front, the shots combine with yours to form a more powerful shot; when at the rear, you have a spread shot. Regardless of configuration, you can hold / to rapidfire.
Some (many?) American copies of the game are plagued with a manufacturing defect (supposedly poor quality PCBs?) that reduce the cartridge's lifespan.
Source: In-game credits
Project Leader: Jun Amanai
Main Programmer: Jun Amanai
Programmer: Takayuki Muraoka
Assistant Programmer: Osamu Yamamoto
Graphics: Ken-ichi Nemoto
Audio: Kenji Yokoyama
Test Players: Ken-ichi Nemoto, John Arvay, Mike Kruse, Rob Boone, Kenji Yokoyama, Jim Hernandez
Special Thanks: Bill Hindorff, Mitzi McGilvray, Tatsuya Uemura