Sons of Camelot: Making a "Blood Bros" clon

I’m going to make a clone of the great TAD Corporation game in 1990, “Blood Bros.
This is a small analysis of said game. The idea is to see how it works to replicate the mechanics in my own game.


Movement of the character and the sight in Blood Bros:

  • The player moves the character in the horizontal plane (joystick) and it moves always at the same speed for one side or the other. 
  • When the player moves the character (joystick), the sight moves at the same time almost twice the speed of the player. That is, moving the character involves moving the sights. 
  • When the player presses the firing button, the character does NOT move and fire.
  • If the player presses shot + movement (joystick), the sight moves while shooting, leaving the character immobile. 
  • The player can dodge while moving, the sight remains still while dodging. 
  • When the player fires, the shots instantly reach the target (there are no bullets crossing the screen). 
  • The player can throw bombs at the target, the bombs cross the screen until they reach the target. 
  • The sight stops at the edges of the screen when it reaches them and stops. 
  • The player stops at the edges of the screen, there is no scroll.

Characters in Blood Bros

  • Player 1 always plays with the cowboy and Player 2 always plays the Indian.
  • Both are virtually the same except for the character and sigth sprite. 
  • The player dies when 1 bullet / bomb touches him, there are no “energy points”. 
  • In the original game the player takes about 3.5 seconds to travel the screen from side to side, the look takes about 2 seconds to travel the screen from side to side (I would say it is almost twice the speed), we will try to follow those speeds.

Stages in Blood Bros

  • The stage has several planes where the enemies move. There are nearby enemies (larger), medium distance and in the distance (smaller). 
  • The scenario is composed of several buildings / destructible buildings that can be in different planes. These buildings / constructions have, therefore, a quantity of “life”, when the buildings / constructions are destroyed they stop making parapet to the enemies that pass behind. The form of destruction is always the same, they crumble down. 
  • There are also objects (such as barrels or rocks), just in front of the players, who act as cover / defense, they can also be destroyed and simply destroyed when they are destroyed. 
  • To advance to next screnn, the player must destroy a certain number of enemies (FOE indicator in the game), the indicator increases each time it is killed.

Weapons, bonuses, bombs in Blood Bros

  • There are 3 weapons, the basic one (always carried by the player), the shotgun and the rifle. The sight becomes bigger when catching a better weapon and it shoots faster and the shots do more damage. 
  • The weapons last a limited time. 
  • When killing enemies they can release bonuses (they give points when picking them up or when they are shot while falling). 
  • When shooting certain NPCs (pigs, dancers, etc.) they can drop weapons or bombs (they are picked up when passing over them or being shot while falling).NPCs do not die, they simply run away.

Enemies and their behavior in Blood Bros

All the screens, except those of Boss, have established a CYCLE of enemies that is repeated. That is, if we have not finished the phase when the cycle ends, the cycle begins again. For example, suppose the cycle lasts 60 seconds:

sec 3: 3 enemies come out on the right, go to the center, shoot and leave on the left
sec 8: 3 enemies leave on the roof of a building, shoot, and flee
sec 12: 1 pig-bonus comes out from left to right

sec 55: 1 enemy left on horseback, throws a bomb by taking 1/3 screen
sec 63: 3 enemies come out on the right, go to the center, shoot and leave on the left
sec 68: 3 enemies come out on the roof of a building, shoot, and flee
sec 72: 1 bonus pig comes out from left to right

etc etc

Technical data

The original resolution of the game is 256 × 224 px .
Can be player by 1 or 2 persons at same time.

What is the FOE bar (enemies)

FOE means enemy,

To advance to next stage, the player has to fill the FOE bar. This is achieved by killing enemies.
Usually any enemy will add 5 points of FOE with his death.
The bar will be filled when you get 200 or more points. At that moment all enemies die and advance to next screen. Will make similar behaviour in my game.