Actors should collide with each other

Spritesheets should go into a registry so they can be looked up by name/ID

Sprites should go into a registry so they can be looked up by name/ID

Actors should go into a registry so they can be iterated over

Actor registry should be able to iterate actors by their layer

World collision geometry should be loaded from object layers on the map

Actors should collide with the world

Actors should be loaded from object layers on the map (position and sprite names mapped to state numbers)

Actors should be able to follow a path defined with a polyline on a layer on the map

Maps should be able to have image layers

Map parallax should work
