Your home planet is under attack by aliens. Join the Planetary Defense Force and help repel the invasion!

Gameplay

PDF is a 3D shooter somewhat similar to a missile defense style game. However, it employs intelligent enemy swarms in full 3D graphics and a deeper gameplay with upgradeable weapons, buyable AI support guns and much more.

Enemies

Drones

Dumb, swarming enemies that are pretty suicidal. They have (weak) laser guns, but do most damage if they crash into their target. They also crash into pretty much anything else that's in their path. They are dangerous because they always appear in swarms, from about 10 to 20 and more drones. A single hit is usually enough to destroy a drone.

Fighters

These fast and agile alien ships prefer strafing attacks. They move in and out quickly, usually in a straight line, blasting away with their on-board dual laser cannons. They do not make much damage, but are difficult to hit due to their speed. Usually deployed in wings of two or four. Fighters can take several hits before they are destroyed.

Bombers

Slow-moving but hard-hitting attack craft that fire missiles and drop bombs. Usually deployed at higher altitudes while other attacks are ongoing as cover, so watch out for their presence. Bombers can take several hits before they are destroyed.

Mothership

Every once in a while, the mothership itself will descend upon its target. A mothership will spawn continuous waves of smaller attack crafts and is itself supplied with several heavy laser batteries that can quickly lay waste to an entire city. Fortunately, keeping the mothership hovering at low altitude is difficult and very fuel-expensive and so is only done as a last ressort, when lesser attacks have failed. A mothership can sustain a large amount of damage before it is destroyed.

Weapon Systems

You begin the game with a small laser battery, which contains four laser guns that it can fire either in sequence (giving you a higher rate of fire) or at once (more damage in one shot). During the game, the weapon can (and should be) upgraded:

Upgrades

• improved firing speed
• improved laser bolt speed (I'm using the Star Wars mechanics where laser bolts are not moving at the speed of light)
• faster cooldown (if I add overheating)
• more damage

== Weapon Types== In addition to the upgrades, maybe there will be other weapon types available as well:

• mass driver (essentially, proximity energy mines)
• plasma gun (wider target area, lightning-bolt like effect that can "lock on" to a target)
• rocket launcher (slow, bad to aim with, but lots of damage, for use against large, slow targets)

but the core idea is to keep it simple, so every weapon will be checked for whether or not it actually adds something to gameplay.

Targets

The attacking forces are trying to destroy vital targets in the city. Each of these targets is protected by a force field. Scoring will be based directly on how many of the targets survive. If all targets are destroyed, the game is lost.

In addition, AI defenders and even the players gun can be attacked and damaged as well. If the player has no defenses left, it will also be game over.

Scoring

Points are given for

• enemy ships shot down
• entire waves eliminated (bonus points)
• targets that survive a level
• ?