Over the two days of work, I built the game from the map forward. What I mean is that my first goal was to get individual map pages rendering on screen. From there I moved on to the game manager component, building out the startup logic and render loop. This lead to the entity system, which in turn lead to the player entity. Once I had the player moving around I built code to check for collisions with obstacles in the map and changing the view when the player hits the edges of the screen. At this point you could explore the whole world map! It was pretty boring though.
Next I started making monsters and items for the player to interact with. Since I had common code to check for collisions, get lists of entities occupying particular squares, etc, the monsters weren’t terribly difficult to implement. The most time consuming part was getting the combat mechanics to a good place where it was challenging but not frustrating.