There is a converter bb sourcecode (inside the html version zip) to make a js file from a dta map. Once converted, you have to open it in  notepad and insert as the first line:

var waste= [

and scroll to the bottom and add to the end of the last line:

];

Basically, it's just a single dimension array that holds the level original data, to be used at beginning and after game over to restart the game.

Also, in the JS version I did not bother with spritesheet support, as this requires a server to work. Therefor, at this time, each image, be it sprite or tile, is an individual file. Animated tiles are insofar compatible, as the original sheet system (eg. mything__ani32x32x4.png ) does still use this filename to extract information about the animation, but then expects individual files to be present, in this example they would be mything0.png, mything1.png, mything2.png and mything3.png,, while the file  mything__ani32x32x4.png is not required. The tiles were originally defined in tiles/tiles.txt , but for the js version this was simply hardcoded in the source, top of function load_tiles(). The source is monolithic with no dependencies whatsoever, meaning this is one js file, containing everything (except for the map data that is included as a js file). As it is only 40kB, it's still manageable. The main task is implemented using  javascripts' setTimeout threading feature and it is a fairly long piece of code, but it allows the various sections to communicate with each other in a direct way, making the result much more efficient, albeit less modular.