The Engine
Game creation engine with built-in BASIC interpreter.
...The BASIC interpreter supports only labels, not line numbers, and the program is written with the built-in editor.
Interpreter and graphics engine run in parallel, in separate threads, and hence interpreter speed is not an issue. The interpreter is not chiefly designed for speed, but for comfortable development.
The editor and command screen use a custom 8 x 8 font on a 64x16 character text display.