• Actors should have beforeTick the same way that scenes do. This is undoubtedly useful as I wanted it several times while making Pipe Puzzle.
• Opting out of tick() should be possible. When a container opts out of ticking, none of its children will tick either. This might be premature optimization, but most game engines do not tick every object on every frame so it's probably good practice ;)
• Some actors like AnimatedActor could be built by a function that adds a few properties to an Actor and gives it a beforeTick func that animates.

• Remove keyboard from tick functions everywhere. Use an event based model for keyboard input instead. Actors/scenes can subscribe to an event and have a function called when the event triggers.

• Pixi.JS has resize events. Scenes should be able to adjust their contents in response to a resize event.
• Percentage-based or viewport-relative units should be used when moving actors on the stage.
• Perhaps something like isLandscape and isPortrait would be useful as layouts often change drastically depending on which dimension is largest maybe in future

The scenes in /examples are my current (manual) tests.

• Rename /examples to /tests
• Create simple test scenes for each type/combination of scene with some uncomplicated actors
• Create test scenes for each combination of actors and actions

That's the simple part.

Eventually, figure out how to do automated testing of Pixi.JS and build support for that into this project. But that's the hard part :)

• Adding actors to the scene after instantiation of the scene object should automatically add them to the mounted container. Perhaps addActors could take an optional argument for a parent actor (or subscene?)
• addActor variant of addActors
• Actors should tick their children automatically
• Maybe I should strive for consistency with lifecycle methods and use actors.add() instead of addActors?

• Ability to pass a function to game.changeScene which could do a transition (e.g. fade alpha value) before changing scene. Maybe by adding it to the beforeMount lifecycle on the scene being changed to?
• Similar to how keyboard is disabled during transitions to/from PauseScene: interactivity with taps/clicks must be disabled during most scene transitions and briefly afterwards