Arduino MOD/XM/IT playpack via pwm pins and no DAC?

I recently discovered the Squawk MOD player, but it only supports 4 sounds: 25% square, 50% square, triangle, noise. It uses the PWM pin 3 to play the music. It can play the specific mod files it had fine.

The reason that I don’t want to use an R2R resistor ladder is because I don’t have the resistors and I don’t even have the money to buy one, so I’m resorting to what I have.

That brings up the question: could I possibly get a full amiga mod file to play from only one or two PWM pins?

If you set the pwm frequency of pin 6 to 62500 hz then you should technically be able to play full mod/XM/IT files on the arduino. But then because of the memory restrictions, you’d have to use the serial monitor to slowly send the music data to the arduino, since the samples would probably take up more space than 32kb.

If anyone can point me in the right direction, thank you.