Airstrike levels and goal oriented game-play

[Eero Tamminen]

Hi,

I'd like to open a discussion about the airstrike levels.

We have now several things which can be used to implement them:
- Background graphics
  - and mask for parts through which one can fly
- Global settings, such as gravity etc.
- Objects[1]:
  - sprites,
  - sprite generators,
  - triggers for other triggers and generators
  What can be done with these:
  - Setup initial objects  and triggers on the level
  - Triggers for things to happen during the level
  - Triggers for level end conditions
- Level configuration system that allows changing these without
  touching the actual game code
[1]  For a list of these, see the Airstrike design structure diagram
      I just updated in the CVS.


To be interesting, each of the levels should have the following elements[2]:
1. A goal (and a variety of related sub-goals)
2. Obstacles (designed to prevent you from from obtaining your goal)
3. Resources (to assist you in obtaining your goal)
4. Rewards (for progress in the game, often in the form of resources)
5. Penalties (for failing to to overcome obstacles, often in the form of
    more obstacles)
6. Information

[2] The list is loaned from the book associated with the "Game On"
     Art exhibition. :-)

What this means in practice:
1) For deathmatch the goal would be to kill the other player (given number
    of times).   For co-operative mode, the goals could differ between each
    level.  They could be moving or destroying objects (in later versions
    this could also including taking control of them or transferring them to
    somewhere else).   Subgoals can be done by triggering other triggers
2) Obstacles are the other players, sprites that obstruct player's flying,
    either just by being inmovable or by following him, and things that
    directly or indirectly harm the player (e.g. missile vs. bonus that
    creates a missile aimed at player)
3) Resources are currently only fuel and bombs, but it could also be time
    (if there would be a time bonus that affects timer triggers). Lack of an
    resource is an obstacle
4) Additional fuel can come from generators or bonuses, bombs come only
    from bonuses.  There are additional "rewards" in form of other bonuses
    such as the one that clones the player sprite (on level 3) or generates
    harmless other sprites
5) Penalties can be added with triggers e.g. for destroying or approaching
    something or just being too late.   For example, there can be a timer
    trigger that will activate a proximity trigger than will trigger
    a missile generator when player approaches a "goal" too late
6) Currently game shows only information about level name, that bombs or
    fuel have ended and reason for level ending, but there should be
    indications about score and number of remaining lives, fuel and bombs.
    (The tricky thing about adding these is that player is an AI object, but
    it's biplane sprite that has these properties...)


To sustain interest:
- The difficulty of levels should increase when the game progresses, but not
   too much.   Usually games have a couple of easy tutorial levels at the
   beginning where the player learns how to:
   - Control his sprite
   - Interact with the game environment
   - Learn how to best deal with different game objects/obstacles
- There should be simple base rules from which evolves complex interactions.
  In Airstrike this comes mainly from the physics based interaction and
  object that behave physically differently (mass, rotation...)
- The game should vary and sometimes surprise the player.  It could offer
  different types of goals, different sprites etc., even different playing
  moods.  For example:
  - Circus level with bright colors, jolly/hectic music[3] and funny sprites
  - Scary level with dark colors, oppressive music and something (e.g.
    missiles, birds etc) that constantly chases the player while he tries to
    accomplish the goal
  - Sombre/relaxing level with pastel colors, ambient music and no
    time limits

[3] We don't currently have any background music, but if that's added in 
v1.1, it would good if it could change per level.


As a conclusion for this long-winded mail, I'd like people to suggest goals
and obstacles for the first six Airstrike levels...

It would also be good if there's a background story.


	- Eero