I am working towards importing and using raw JSON files from the "Tiled" editor, which supports animated tiles, layers, flipping tiles horizontally/vertically, multiple tilesets. Features the PlayDate API doesn't do (well you can do layers, just not as easily)
I've got most of the above working, including dirty rectangle, and the tweening system for tile animations, and character X/Y/alpha plugged into an event system so I can queue commands (ie: you'll be able to tell a character to move north, north, east, wait till done, then tween alpha from 100% to 0%)
the main problem is Lua does not like the insane file format Tiled uses where it merges 6 datapoints into a single large number. So most of the blank parts of the map are tiles that are supposed to be flipped horizontally/vertically.
It does make minor changes to Tiled's data:
Tiled's properties are merged into the map's/tileset's data, and so is the class (noautoplay name=test becomes [noautoplay] = true and [name] = "test") and the layer will only be drawn if it has a [z] property to define it's z-index
Characters exist on a given layer, and they're sorted by Y then X. And any tile row on the same layer is drawn after the characters in the previous row, which is how the elevator door shows above the character on it's same layer. They have states (Mark S is currently in "standing" state) and when finished the "walking" state they'll automatically return to the default state (the first one declared)
It will use lua files for it's scripting, unlike Pulp which has it's own scripting language. Which saves me a ton of work.