Progress so far:

[x] Have a basic start screen.
[x] Have start-screen UI for starting the game and closing the application.
[x] Have a single playable level allowing the player to hop between platforms in 3D space towards a goal.
[x] Have a goal that ends the level.
[x] Have a death mechanic that resets the level. 
[x] Have UI that explains to the player that they've actually died when they die.
[x] Have an end-level screen that tells the player they've completed the level.
[x] Have an end-game screen that tells the player they've completed the GAME.

[x] Add pause-menu launched when player looses focus.
[x] Add behavior to lock-cursor on pause-menu resume.
[x] Pause/slow game-time while pause-menu's displayed.
[x] Flip gravity mechanic.
[x] Level 2
[x] Start Screen Instruction.
[x] Patrolling enemies.
[x] Collide with enemies death-mechanic.
[x] Ability to shoot projectiles.
[x] Projectiles kill enemies.
[x] Add collectibles mechanic.
[x] Level 3

This week's implementation goals are:

[x] Audio
[x] Heads Up Display showing collectables.
[x] Level 1 upgrade level-design. 
[x] Level 2 upgrade level-design.
[x] Level 4
[ ] Unlockables.