Battle Intensity can be measured in many ways:
* number of bullets fired in a given volume of space or time
* number of active enemies
* number of enemies aware of the player
* player health
Games should react to battle intensity to give a heighten emotional feel. The player should feel more threatened or in danger. Players also pick up on these queues and can look for a place to hide or if they should run away. Battle intensity also needs to decay. The shift from an intense battle to normal exploration should not be too abupt. The build up and ramp down needs to feel nature.
Some ways to communicate battle intensity:
* adjust edges of screen when taking damage or in severe distress
* change the music from ambient music to combat music
* increase volume or tempo of music
* increase smoke or fog to simulate gun smoke filling a room
* tint the screen subltly
Battle intensity needs to be subtle but recognizeable. Players will certainly notice when the cues are not present. The cues should not be overbearing or too noticeable or the element of surprise might be lost. A player would know he's about to go into a boss fight because of a music change when maybe the boss is supposed to get the jump on the player for example.
An excellant example of battle intensity is the Rock Band and Guitar Hero backgrounds. The crowds become louder, the animations more exaggerated, the colors more vibrant. You KNOW when you're playing well even if you don't look at your meters.
