[hyp0]

That sounds way professional!

ZX81 game programmer here. A game shop said they'd stock it, but I was too exhausted from finishing the game to deal with the "business side" of arranging duplicating tapes, professional labels etc. (I didn't realize you could just do them one-by-one, by hand. Start small.) But it did get me a programming job at a games company (the interviewer later told me he didn't think a game that good was even possible on a ZX81).

Business side is important. Good to learn at 15.