Hi Kaiju! To import the stuff you need to open the Resource Manager and add the tilesets to the "img/tilesets" section :) The water animation is not compatible atm cause it has a loop of 13 frames and the rpg maker max allowed frames are 4!
Once I've imported them into the Resource Manager and added the tileset to a map (in the A5) category and start mapping things out, the screen is just black once I launch a playtest. I must be missing something super obvious haha