King Art Games released a faction preview featurette for Iron Harvest, starring the Rusviet faction. It offers a glimpse into some of the units available for them, including the SHV-69 Serp.
SHV-69 Serp is Rusviet's brute of a mech, in all possible meanings of the word. It is a slow melee unit but bulky enough to take the punishment until it reaches the enemy. Furthermore, no obstacle will prevent Serp from advancing as it tramples everything in the path.
While that sounds badass and reminds of the Atlas from BattleTech, these features are complemented by the mech being the biggest possible representation of the Rusviet faction. Namely, it has two sickles for weapons, and as you probably know already - a hammer and a sickle are often seen as the symbols of communist nations. Furthermore, the name Serp literally means "sickle" in Russian.
SHM-60 Groza is the hybrid unit as it's neither mere infantry nor a proper mech. These melee-favouring soldiers are equipped with exoskeletons that also have jump packs, making them fairly similar to the assault marines from Warhammer 40K series.
SHM-68 Nakovalnya is the polar opposite of the two units described above. It favours long-range as it's an artillery machine that can shoot out enough rockets to blot out the sky. Not literally, but the sheer number of projectiles fired from a single unit is pretty amazing and reminds a lot of the BM-21 Grad, the real-life counterpart.
Olga Morozova is a hero unit that is highly reminiscent of Tanya from Red Alert series as she can annihilate infantry on her own or demolish structures and mechs, provided they find themselves near her explosives. The main difference here is that Olga is seen riding a tiger into battle.