final improvements

this is a maintenance update fixing some of the remaining issues in the Improve My Game Jam version that popped up while playtesting.

✱ first encounter now has only 1 enemy
✱ Spike and Honey effects are properly cleared now
✱ fixed Spike damage to enemies with Plus cards
✱ options are persistent and remain across resets
✱ raised chance of enemies using cards
✱ add enemy card sound effect
✱ more useful header messages for blocked enemies
✱ fix animation when entering game from credits screen