However, the spacetime spectrum is not supersymmetric and, in fact, does not contain any fermions at all.
In dimensions greater than two, the ground state is a tachyon so the theory is unstable.
These properties make it similar to the bosonic string and an unsuitable proposal for describing the world as we observe it, although a GSO projection does get rid of the tachyon and the even G-parity sector of the theory defines a stable string theory.
The theory is used sometimes as a toy model for exploring concepts in string theory, notably closed string tachyon condensation.
Some other recent interest has involved the two-dimensional Type 0 string which has a non-perturbatively stable matrix model description.