* Adds pkg/savegame to store user progress thru Level Packs.
* The savegame.json is mildly tamper resistant by including a checksum
along with the JSON body.
* The checksum combines the JSON string + an app secret (in savegame.go)
+ user specific entropy (stored in their settings.json). If the user
modifies their save file and the checksum becomes invalid the game
will not load the save file, acting like it didn't exist, resetting
all their high scores.
Updates to the Story Mode window:
* On the LevelPacks list: shows e.g. "[completed 0 of 3 levels]" showing
a user's progress thru the level pack.
* Below the levels on the Detail screen:
* Shows an indicator whether the level is completed or not.
* Shows high scores (fastest times beating the level)
* Shows a padlock icon if levels are locked and the player hasn't
reached them yet. Pops up an Alert modal if a locked level is
clicked on.
Scoring is based around your fastest time elapsed to finish the level.
* Perfect Time (gold coin): player has not died during the level.
* Best Time (silver coin): player has continued from a checkpoint.
In-game an elapsed timer is shown in the top left corner along with the
gold or silver coin indicating if your run has been Perfect.
If the user enters any Cheat Codes during gameplay they are not eligible
to win a high score, but the level will still be marked as completed.
The icon next to the in-game timer disappears when a cheat code has been
entered.
Noah Petherbridge
672ee9641a