The SU-85 was a SPG developed by the Soviet Union. It had very good armor, a very powerful main gun, but it did not have a 360° turret, or a turret at all. It had 15°of rotation on either side horizontally, same with vertically. . Because of the SU-85 not having a turret, it could be easily disabled by destroying the tracks. It had a frontal plate of 45mm, and had a 85mm D-5T gun. The tank was later outfitted with APDSH shell, making the tank’s gun even more powerful. The tank had an interesting turret, being a sphere instead of the regular rectangular turret that can swivel. The main reason why they made the turret into a sphere was because otherwise the recoil from the gun would pick the tank up the ground by a few feet. It was very powerful otherwise, being able to take out German or Italian tanks at incredible ranges.
The SU-85 had very thick armor. The upper left and right front plate were 45mm thick, and heavily sloped so it could easily deflect many oncoming shells. The SU-85 had very thick from armor, however the backside armor wasn't as thick. The color on the SU-85 looks oddly more green than other Russian made tanks. It had very thick armor for the time and because of that, it helped it stay, and live, throughout its time in WW2.
The SU-85 has a massive 85mm heavy anti-tank cannon, being able to take out almost every German made tank with ease. Sometimes when a SU-85 would hit a armored vehicle, the shot would not explode and instead go right through the front and out the back, making some types of chemical or HEAT and HE shells not the best when used with it. A lot of the shells used were shells that didn't rely on thick armor, but shells that fragmented upon impact.
There weren't many flaws other than the turret not having 360 degrees of rotation, which still was a problem, but another flaw (not really a flaw, more like too efficient guns), was the fact that the cannons piercing ability would make the shell fly straight through the armor of enemy vehicles, and not exploding in the middle of the target.
Kharkiv model V-2 V-12 was the engine the SU-85 tank hunter used. It had about 500 horsepower, making the SU-85 a decently fast tank in WW2. It had a pretty good transmission as well, so it had pretty good speed and also could climb hills somewhat well. It could get to vantage point before many different tanks, making it be able to get to places that some tanks couldn't.