This just sounds like a different version of mycoprotein or quorn.
Not to discount their efforts, the more like them the better.
This is amazing - is there a catch? What's up with the "Finnish investors only" rule?
Some countries have mechanisms to allow restricted investment by, essentially, retail investors, without being a full public company. These are usually idiosyncratic enough that they're country-scoped and not open to foreign investors.
The company does have at least some non-retail foreign investment.
Seriously anxious investors can usually set up a local operation to channel funds and build networks.