Wierdness: so long as I start a new game each time, the game plays out as it should. However, if I recall a saved game from disk, the creatures appear not to battle and are effectively immortal.

This may or may not be connected with the moveAllCreatures() method in Swamp.class appearing to call moveCreature() in Creature.class at least twice per Creature.

If it were always twice, I’d be a little less confused.