Thank you for playing and kind words!
The game loads nearly instantly because the game itself (index.html and WebAssembly executable) is just about 60 kB in size. The rest of it (almost 2 MB) is sound assets in .ogg format, most of which is music (two tracks I have hastily composed, one for the title screen, other for the game itself), while sound effects are only about 115 kB. There are no graphical asset (files) since the graphics is hard-coded, some of it is in arrays (e.g. splash screen logo, 8x8 font and 3x5 "digit font"), some of it is proceduraly generated.