And I said that in response to the guess that maybe the 62,000 lines of code was all game logic, which is absurd.

Game logic, like, "when the player presses the fire button, spawn a missile" and "this enemy goes up 5 units, then goes down 5 units, then repeats". That's not the kind of thing that will change much from one metroid clone to another, regardless of what technology is used to make them. It is practically always the smallest part of the final product. And to have the game logic's source be bigger than the entirety of an almost identical game, with handcrafted levels, art, and engine included? It's absolutely absurd.

It was in service of the point above: that code is probably all the engine, which means that, yes, it probably was a waste of time, since engines made by professionals are available for free. At best, it's a line on a resume.