Implement pause menu

[nucleartide]

User Story

screenie.mov

• When P is pressed, pause the game and show a pause menu
• Pause menu contains (paused) text
• Pause menu contains a resume button for resuming the game
• Pause menu contains an Exit to menu button

Will not do for the sake of time:

• Add current score, current level, and whether current score is high score to pause menu
• Add high score (with high score level) to pause menu
• Add a confirmation modal when "Exit to menu" is clicked, that asks "Are you sure? You'll lose your current level and score", along with Yes/No buttons

Playable build

https://drive.google.com/file/d/1XWMMkkKRk5EnyUC8Yutu7vKtq4TCQf3H/view?usp=drive_link

Dev checklist

• First draft. Implement a working first pass at the feature. If it helps, try thinking about data (model), presentation (view), and logic (controller).
  • Design by contract. Write pre-condition, post-condition, and invariant assertions to catch bugs before playtesting.
  • Unit tests. If needed, write unit tests to tease out edge cases.
  • First playtest. Thoroughly playtest until you are confident that the feature (and existing features) work. This also exercises the code paths with contracts.
• Final draft. Perform a general review of Files changed and revise anything that needs to be cleaned up.
  • Run unit tests.
  • Final playtest. After the changes above, playtest through the game one last time to ensure that everything works.
• Fill out the pull request template. Self-explanatory.
• Remember the GIFs. Include a recording of what's going on!
• Update readme. Maintain a list of pull requests for easy access later.
• Merge. Merge into master.

Release checklist

• Build. Cut a new build in Unreal. If the game doesn't build, fix until it does.
• Tag. Once built, tag the latest commit on master with the latest version string.
• Upload. Upload build to Google Drive.
• Link. Add link to this pull request.
• Priorities. Prioritize items on work board.
• Next task. Tee up a pull request for the next feature.