This program contains both code and data that I'm not the author of:
* the levels are exact copies of those from the original game BOOM
* the graphics and font are adaptations of the original game's ones
* some (very few) routines were taken from the CE toolchain/libraries,
  to list them all: cstartup, ccleanup, gfx_Begin, gfx_End, kb_Scan -
  they were released under the GNU LGPL v3.0, and their code can be
  found at: https://github.com/CE-Programming/toolchain/blob/v8.8/