Raptor is one of the best top-down arcade shooters ever made for the PC.
Raptor: Call of the Shadows filled a hole in the PC game world for just such a shooter when it was introduced in 1994 by Apogee. Developer Scott Host was brought into Apogee to develop the game following his successful Galactix title, another top-down arcade shooter that was more limited in scope and technical capability, but showed promise. The resulting "Raptor" stood for the next five years as the gold-standard top-down arcade shooter. It is easy to see why, if you yourself can get the game to run on a DOS emulator.
You are a Mercenary in control of the advanced fighter plane, Raptor. You are hired by Megacorps to fly to other planets to take out competing firm wares. You earn cash for every enemy machine downed, and that money can be used between missions to buy upgrades for your ship, including miniguns, auto-tracking weapons, lasers, and similar powerups. Unlike many top-down shooters, the player can take a certain amount of damage before being destroyed, though there is only a single "life." You are not granted powerups in the missions themselves, only money. After all, you are a mercenary.
Raptor has no dramatic plot line or trying puzzles. It is a simple, attractive, and well-executed example of the top-down arcade shooter. The early levels are challenging without being frustrating, and the upgrades make you feel like you are truly unstoppable. The graphics - meaning the artwork - were entirely raster-based yet still look great today, if a bit chunky on a larger monitor. The bosses are large and impressive, with the requisite spirals of nearly unavoidable flak, lasers, and bullets. The effects even sound great, despite their age. Digitized explosions and weapon sounds are appropriate to the mayhem of a high-powered piece of technology cutting through dozens of helplessly inferior enemy drones.
However, getting your sound card to work with the MS-Dos software is often the hardest part of the game. With ship upgrades Raptor actually gets less challenging as you progress. You are unlikely to mind as you triumphantly plow through the enemy with your new toys, though.
Raptor is definitely a fun game exemplary of its genre and should not be missed by fans of arcade shooters.