## Levels:

- ignore comments in lvl files

- check  when sphere bounces from  one end to the  other endlessly w/o
  any solids in between. this is a game lock and equals game over

- Start the game  end timer and add a score FIXME:  put the actual max
  reachable score  into the  level definition  along with  the minimum
  steps required to reach it, also add a step counter

- Grid Observer:
  https://github.com/mlange-42/arche/issues/374

- Add some final message when the player reaches the last level, start
  from scratch or a message to buy me some beer, whatever

- Check player-player collisions!

- Add  player mergers, possibly as  an option, so maybe  we could have
  different primary  and secondary  players: one  pair can  merge, the
  other not. Like S + s and M + m or something.

- Add shaders for animation (player destruction etc)

- Add player HUD + Stats (as hud_system!)


## Collider Rework

- do not use the map anymore for collision detection
- central collision_system
- add Collider component with callback funcs to call on certain events
- callback types:
  - rect intersect (== future collision)
  - collision resolve (set new position)
  - pass over foreign rect (to e.g. change sprite while flying over sprite)
  - pass over done (switch sprite)
- check  for all  moving objects against  non-moving ones  like moving
  obstacle, player, bullet, laser
- check if executing callbacks within query loop is allowed
- callback  function needs to be  able to modify other  components, so
  possibly use observers for them, e.g.:
  Collider.IntersectResolve => func(newpos) {player.pos = newpos; player.vel = stop}
- in the end it must be  possible to add new entities without the need
  to write a collision check for them, but have collision detection anyway!