Polyarnaya (Polaris) consists in a Proton/Soyuz-inspired rocket that runs in hypergolic propellants. This vehicle is meant to launch from Baikonur or Plesetsk Cosmodromes, featuring a simple launch pad (with cool flames) and hot-staging.

Specifications

Height: ~45 m
Stages: 3 (5 RHE-1 engines on first, 4 RHE-2 engines on second and 1 RHE-2 engine on third)
Simulated Propellant: UDHM/N2O4
Core diameter: 2.80 m
Fairing diameter: 4 m
Capacity LEO (Baikonur 45°): 5.800 kg

Some recommendations:
-Like Enceladus (my other rocket, may you want test it), Polyarnaya come with a simple Vizzy that just take-off the rocket and in this case, runs the flammable launch pad. Toogle AG:2 ALS on and good luck.

-Hot staging: I highly recommend to stop vehicle on a steady attitude and throttle back first stage to around 50% close to separation, then waits the tank level reach 2% to activate the second stage. If all goes well, you'll see a customized effect and the separation.