SY300 Chiptune/8 bit sound

[baga]

Hello there everyone, I'm struggling since months to achieve a chiptune/8 bit sound on the SY300 unit.
I'm looking for something like that: https://www.youtube.com/watch?v=iIfGD0EkuhE, something like old Gameboy sounds.
Ideas (or patch) anyone?

[Rhcole]

OK with you if the sound is monophonic, doesn't work well with chords?

[baga]

OK with you if the sound is monophonic, doesn't work well with chords?

Yeah, it sounds a little messy, but I need it for playing single notes!