I don't see a noise source on the M32. Maybe I'm overlooking it. But Intellijel makes a 1U sample/hold/slew/clock/noise module. It would be a great addition.
When you're ready to grow: think about effects like reverbs, delays, overdrive/distortion. Also a small clockable sequencer like Mimitec Digitalis would go well for some creative fun. Sequencers are great sources for modulation apart from generating notes.
Take it slow and experiment recklessly. This is a good entry point but you'll probably push the M32 out of the case within 6 months to a year.