I've been trying to figure out the the file formats for Super Mario Maker saves and this is what I have so far, hope its helpful (note that I only used my own Mario Maker levels to test this so you might want to double check it yourself): *.cdt file The file is in big-endian. All addresses not listed are 0x00. https://docs.google.com/spreadsheets/d/1k4f6TZ6jvVbWVsLFAYLYfZMcd2CUdNObNBvxa3QGSwM/edit?usp=sharing I still need to figure out the format of tiles in cdt files. *.tnl file Thumbnail file. 8-Unknown bytes and then a default JPEG file. Always 51 200 bytes.