The construction is at least at face value a pretty simple ARX cipher - the only real questions being why choose the specific rotation constants they do for each round (ciphers developed in the open usually do things like key off digits of pi) and why compose specifically via xor, then add, then rotate in each round, rather than more of a blend.

If this style algorithm does indeed have an intentional backdoor: That's some crazy mathematic chops and I'd love to read the theory behind how it (the intentionally weak algorithm) was found (since hopefully that leads to a natural way to generate stronger algorithms, or at least check for weak ones). That'd be a valuable takeaway for the security community once the secret's spoiled, if it is the case.