Hold on guys. Redherring is right. There is a problem with the checkpoint tile type. Demonstration in the video below:
[media]https://youtu.be/tky1fUVJuEw[/media]
+ The "Warp to Underworld" tag has no effect on the technique suggested in this thread.
+ Checkpoint-related warps appear to be dependent on the map the player was placed to start at the NESMaker's interface. So for exmple:
+ If the player is set to start on the Overworld, then a death-triggered warp after touching a checkpoint tile will continue to warp the player on the Overworld map.
+ If the player is set to start on the Underworld, then the same death warp will continue to warp the player in the underground.
With this in mind:
+ If a player starts out on the Overworld,
+ Enters an Underworld dungeon,
+ Touches a checkpoint tile and dies
Then the death triggered warp will place the player on the same checkpoint screen coordinates on the Overworld.
The video shows this in action.
The script should be revised making sure the player warps to the correct world map.
EDIT: As a workaround you can make the corresponding Overworld screen completely black then set a warp tile where the player pops up to send you back into the underground. It's not ideal but it works.