BDef is a tower defense strategy game in which you must defend your base from wave after wave of invading enemy bots. Plan your defense tower placement wisely so as to guide the enemy bots through a path that will ensure they spend as much time as possible within the effective ranges of your defensive towers. BDef is streamed so levels will continue to download while you play the game.
The object in BDef is to prevent numerous waves of enemy forces from reaching your fortress. Each time an enemy reaches your fortress it will become damaged until the structure is no longer sound and the game is lost. The amount of damage your fortress can withstand is listed in the lower part of the HUD to the left of the "Wave" indicator and is complimented with the image of a heart. There are various different types of enemy bots which do differing amounts of damage to your base.
In order to prevent bots from reaching your fortress you must build a maze of defensive towers for them to pass. To place a tower left click on a button that represents the tower you desire to place, located on the right side of the HUD. Upon selecting a tower to place you will see the tower placement icon, a green tower icon indicates that a tower can be placed in the current location where a red icon indicates a tower cannot be placed. Towers may be placed anywhere in the play area except on bots, obstacles such as trees and rocks, or in an area that would block the enemy path to your fortress. The orange number in the upper right corner of each tower button represents the amount of scrap metal required to build that tower, you can find the amount of scrap metal you currently posses listed in the top of the HUD labled "Scrap." Each time an enemy bot is destroyed you will collect scrap metal, different bots yield varying amounts of scrap.
Towers may be placed or upgraded while the game is playing in real-time or while the game is paused. The playback buttons are located in the top of the HUD to the left of the "Scrap" indicator. The game starts out in paused mode in order to begin playing press the play button. Upon clicking the play button it will turn into a pause button and the game will begin to play, to pause the game press this button again and notice that it will turn back into a play button. Next to the play/pause button is the fast forward button, clicking this button will enable 2x play and the game speed will be increased by 100% while not paused.
Towers may be upgraded or deconstructed at any time. To upgrade or deconstruct a tower simply left click on the tower to bring up the tower's information card. The number on the deconstruct button represents the amount of scrap you will receive should you choose to deconstruct this tower, the number on the upgrade button represents the amount of scrap required to perform the upgrade. The upper portion of the information card lists the current tower statistics while the lower portion lists the statistics for the next available upgrade. Each tower comes in three variants Mk I, Mk II, and Mk III. The first tower you place will be the Mk I variant.
Finally you may change the volume, enable blob shadows, change anti-aliasing settings or surrender your current game via the options menu which can be accessed from the "Options" button in the lower left of the HUD.
Move the camera up, left, down or right using the W, A, S and D keys respectively or the arrow keys. The camera can be zoomed using the scroll wheel and rotated by holding the middle mouse button and dragging the mouse left or right.
Each level in BDef consists of one or two entrances, an exit and numerous obstacles that enemies cannot pass through and towers cannot be placed upon. Enemies will enter through either of the entrances and attempt to reach the exit while avoiding obstacles and towers. The obstacles, such as trees and rocks, in each level are placed at random so your game play experience will differ each time you play. Unlike the other levels VSim additionally places two entrances and the exit in random locations to further vary the game play experience.
Cannon Tower: The front line of defense this ground defense tower has a short range and high rate of fire. The cannon tower is most effective against light units such as the Bot, Truck Bot and Spider Bot. 12 scrap metal to build and 4 to upgrade.
Artillery Tower: Artillery has a longer range than the cannon tower which allows it to be placed behind cannon towers effectively. This tower targets ground based units and is most effective against heavier units such as the AC Bot, Tank Bot and Rocket Bot. 15 scrap metal to build and 5 to upgrade.
AA Cannon Tower: A cheap anti aircraft weapon the AA tower boasts a medium range and decent fire power. The AA tower prefers to fire upon light aircraft if it's not already firing upon heavier craft. The AA tower will prioritize Drone Bot then Bomber Bot then Battle Bot. 20 scrap metal to build and 8 to upgrade.
SAM Tower: The surface to air missile site is the most effective means of aerial defense with a very long range and excellent firepower. Unlike the AA Cannon the SAM tower prefers to fire upon heavier units and will prioritize opposite the AA Cannon. 41 scrap metal to build and 15 to upgrade.
Spider Bot: Light unit that yields 1 scrap and deals 1 damage.
Bot: Light unit that yields 2 scrap and deals 1 damage.
Truck Bot: Light unit that yields 2 scrap and deals 1 damage.
AC Bot: Medium unit that yields 2 scrap and deals 3 damage.
Tank Bot: Heavy unit that yields 3 scrap and deals 4 damage.
Rocket Bot: Heavy unit that yields 4 scrap and deals 4 damage.
Drone Bot: Light unit that yields 1 scrap and deals 1 damage.
Bomber Bot: Medium unit that yields 2 scrap and deals 3 damage.
Battle Bot: Heavy unit that yields 3 scrap and deals 4 damage.