Changes
/* Technical */
* 2048 bytes for tile graphics. These are defined per-level. These are copied from &31e0 in 4 parts. There are 128 possible tiles. Runtime ranges: &e600-&e800, &ee00-&f000, &f600-&f800, &fe00-&ffff.
* Tiles are 4 pixels wide and 8 pixels tall. Each tile's graphics uses 16 bytes. Tiles are stored uncompressed, left-right and top to bottom.
* Tile "Macro tile map " uses 64 bytes. Each byte seems to describe a block of is 4 tiles, 4 wide and 1 9 tiles tall. ItMacro tile map's runtime location is at &BF90. This byte is used to lookup into data Data at 9600 which describes the 4 tile defines actual tiles to use.
* Sprites for all levels are loaded at once and use ~13KB. They are located at &4a80-&7fff in main ram.
* The game doesn't use hardware scrolling and uses a reduced screen and heavily uses the invisible areas of both screens to store code and data.
