alt Hacker NewsI mean, I could be wrong as far as Harry and DN2 sharing an engine, OTOH Apogee did a -lot- of engine reuse (Bio-Menace used a CK4 variant, Monster Bash using an evolved FAST..)
Although, mea culpa, DN1 engine is not necessarily CK but the programmer has credited Carmack in helping with the drawing assembly...
Harry was written by an Australia, John Passfield, on his own and published by apogee (I forget but apogee might have provided some art support). John is still making games today!