In Outer Regions, the player travels from different planets; they consist of a lunar body (moon), a red planet similar to Mars, an ice world, a volcanic world, and finally a space station.
Tango Sector and Outer Regions each have a special "night wave" with its own theme music. The night level in the Tango Sector is a well-illuminated city in Wave Eight, while the Outer Regions' is the "dark side" of the lunar body.
Gameplay
Enemies and credits
Enemies are destroyed purely for money. Most enemies move in pre-determined paths. Some enemies will try to crash into the player. Turrets also aim to hit the player. There are no obstacles to avoid (except the enemy ships themselves). While flying enemies are the most numerous, many ground targets (buildings, ships, vehicles, turrets) can be destroyed as well.
Bosses appear at the end of each wave or even halfway through the later, more difficult waves. In the Outer Regions, the bosses are ground bases where the player has to take out their various component weapons.
For each target destroyed the player earns credits. The amount of credits earned per enemy destroyed is usually proportional to how tough or dangerous it is, with some of them dropping additional credit bonuses.
The Raptor jet is particularly durable compared to player-controlled craft of other scrolling shooters, which can be destroyed with a few hits. However, there are no "lives" so the game is over when the player dies, although the player can reload a recently saved game.
The player can decide to end a level prematurely, in which case they will lose all the money acquired since starting the level. Damage sustained will remain though, as will collected weapons - as such, one technique to rapidly collect money is to start a level that has an expensive, collectible weapon at the start, collect the weapon, quit and start over. After a couple dozen iterations or so, selling the gathered weapons will provide enough cash to buy most "equipped" weapons, at least the basic auto-tracking turret, and a couple of phase shields - enough to handle most levels as a Rookie.
Weapons and shields
The player starts out with only the default machine guns, and will eventually be able to buy or collect more weapons using a credit and purchase system menu before starting or after finishing a wave.
There are two major categories of weapons: the first type is always active (all carried weapons of this type will always fire simultaneously whenever the player shoots), and the second type is selectable. During gameplay, when firing, only the currently selected selectable weapon will fire, though the currently selected weapon can be dynamically switched to deal with the appropriate situation. Some selectable weapons can only hit airborne targets, others only ground targets, while a few can hit both.
Some of the more original weapons in Raptor, compared to other shoot 'em ups, are the two types of selectable auto-tracking turrets. Other notable weapons are three selectable cannons with expensive prices, that fire continuous instant beams capable of penetrating and destroying multiple targets in one shot.
In its own category is the megabomb, a one-time use weapon which destroys everything on the screen including enemy projectiles, except for the toughest enemies (such as bosses) in which case it will damage them. It can either be picked up or purchased; a maximum of 5 megabombs can be carried at any given time.
The Raptor jet is protected by 100 points of regular shielding, which regenerate extremely slowly, when the player isn't firing (except in the Elite difficulty, where it doesn't regenerate). There is also another kind of shield, called the phase shield, that adds another 100 points of shielding. Unlike regular shielding, phase shields do not recharge (unless the player collects a regular shield power up). Up to 5 layers of Phase Shields can be purchased in the shop. However, it is possible to go beyond 5 layers if Phase Shield powerups are picked up in-battle. When the regular shielding goes lower than 25%, the ship starts taking "physical" damage: each enemy weapon impact will cause an equipped weapon to be destroyed, starting with the currently equipped selectable weapon.
Last but not least, the player can purchase a single utility, the Ion Scanner to measure the energy and damage meter of any boss confronted.
The craft's firepower cannot be upgraded gradually, the best the player can do is pick up or buy cheaper weapons and hope to save up for the expensive ones. Since selling a weapon will only earn back half of its credits, this means that many players try to hold out until they can afford the most expensive weapons, instead of buying medium weapons as a stopgap.
