Lets start with how maps are different in Stage 2 and Legacy.

---The only available maps in Stage 2 are Wraith Trap, Distillery, Weather Control, Orbital Drill.

---The following maps have been removed, the ones that stayed have been reworked:
Armory, Aviary, Barracks, Dam, Fusion Plant, Medlab, Refueling Tower, Rendering Plant, Broken Hill Mine, and Broken Hill Foundry. All these maps are still available in Legacy.

---Since the Defend Gamemode was removed, here's the list of maps removed from said gamemode: Colonial Water/Power, Kings Fort, New Calico, and Salveron Industries.

---All available maps have been reworked, that means vegetation removed, weather reworked.
(So "weather does not try to kill us"~Markov)

---A Special Halloween "gamemode" for Gorgon was exclusive to Wraith Trap, where the path to the center trap is set in a spiral, and the trap is surrounded by acid! Eggs spawn in locations as well, which players can shoot to prevent minion spawns.

---The gamemodes Rescue, Evacuation, Defend, and Nest have been removed. Legacy still features these game modes.

--- In Defend, hunters must protect an evacuation ship from a Stage 3 monster. Minions spawn regularly and will actively destory generators, and eventually the refueling station. If the monster destroys the refueling tower, or kills all hunters, Monster Wins! If the hunters successfully defend the generators for a set duration, or kill the monster, the hunters win!

---In Evacuation, players and monsters embark on a special set of 5 missions around Shear, which includes all game modes; Hunt, Defend, Nest, and Rescue. Special Effects are added as well.

---Hunt and Arena are the only gamemodes that have not been changed or reworked; their gameplay mechanics have stayed the same, save for some balancing.

This sections will go over how different hunters were in Stage 2 and Legacy, and in terms of availability.

---Stage 2 Exclusive Characters:
Support: Battle Cabot (Babot)
Medic: Quantum Caira, Paladin Parnell (Qaira, PaPa)
Trapper: Electro Griffin (E. Griff)
Assault: Renegade Abe (R. Abe)
Monsters: Glacial Behemoth (Bob-sicle)

---Characters Available In Both Versions:
Support: Hank, Tech Hank, Cabot, Sunny, Bucket, Kala
Medic: Val, Rogue Val, Slim, E.M.E.T, Lazarus, Caira
Trapper: Maggie, Wasteland Maggie, Griffin, Abe, Crow, Jack
Assault: Markov, Blitz Markov, Hyde, Parnell, Torvald, Lennox
Monsters: Goliath, Meteor Goliath, Behemoth, Kraken, Elder Kraken, Wraith, Gorgon.

NOTE: In Stage 2's early release, Behemoth was temporarily unavailable due to reworks in physics and movesets.

Class Abilities
Legacy:
Assault has a personal protective shield, much like Hanks shield, but for himself.
Trapper has Dome, and the only one who has dome, no planet tracker. Dome was thrown and took time to activate. Dome was set for 1 minute, and takes 1 Minute to recharge.
Support has cloaking field for his teammates.
Medic keeps heal burst, Rogue Val had a passive healing field, and a personal heal burst which restores her to full hp

Stage 2:
Assault has a personal protective barrier, which negated 55% Damage (Less, for R. Abe).
Trapper has planet scanner to track the monster's location. Every Hunter has a dome, and it's cooldown was 80 seconds. Dome would prematurely drop if any significant damage was done by either side.
Support has shield burst, which gave all allies in range a small shield. Bucket had a class cooldown reset ability instead.
Medic keeps healburst, Qaira has a healing field which would heal nearby hunters overtime, instead of in a single, instant burst.

---Monster Abilities
Monster Abilities haven't changed much in Stage 2, much of the updates to their abilities was just bug fixes (Behemoth, Gorgon most notably), so here are some notable differences to watch out for.

---Wraith has Isolation in Stage 2. (To be perfectly honest, I don't know if this was a thing back in Legacy). Isolation is a passive ability; if a hunter was 60m away from the Wraith, or 20m away from a teammate, they would gain Isolation stacks. Isolation would increase the damage of the next melee swing by 60, stacking up to 5 times.

---In Legacy, Gorgons Mimic would sometimes cause her to become stuck in position after deployment. This could be fixed if the player paused and clicked "Take a Break" to go afk.

---In Stage 2, Behemoth was much easier and smoother to control. Legacy Bob would stop rolling at the slightest bump, and would get stuck when rolling down cliffs.

Perks & Hunting
---Hunters do not have passive HP regeneration in Legacy, and wildlife was much more dangerous.

---Hunters have only 9 Perks in Legacy, and would rank from 1-3 Stars.
1 Star= Weak, 2 Star= Stronger, 3 Star= Strongest.
The Following Perks: Capacity, Damage Increase, Damage Reduction, Reload Speed, Weapon Swap Speed, Jump Height, Jetpack Recharge, HP Regen, Movement Speed.

---Monsters also only had 9 Perks in Legacy.
The Following Perks: Armor Regeneration, Climb Speed, Ability Cooldown, Damage Reduction, Damage Increase, Feeding Speed, Movement Speed, Smell Range, Stamina Increase.

---Elite Wildlife perks stayed the same, save for some balancing.

---Stage 2 has many more perks to choose from. You can choose 3, and would rank from Bronze (Basic), Silver, and Gold (Strongest Perks). There are many perks here, so i'm not going to list them in this guide. Most of the perks were combinations of the basic 9 perks, save for some extra bonuses in some.

---Stage 2's Power Relay would get stronger based on proximity of Hunters. In Legacy, it's health is set, and takes roughly 30 seconds to destroy.

---Jetpack management was much easier: Traveling up walls doesn't consume jetpack fuel, and boosting was easier to manage fuel with.

--In Legacy, every time a monster evolved, he got to choose to level up abilities 3 times per evolution. Stage 1: Pick 3, Stage 2: Pick 3, Stage 3: Pick 3. In Stage 2, You started by leveling abilities 4 times, At Stage 2, 3 times, and at Stage 3, 2 Times.

Hopefully this helps inform the main differences between Legacy and Stage 2. This guide was made solely by me, but with the help of those in our Discord, Evolve Reunited 2.0[discord.gg]. Gameplay mechanics are regularly discussed there, and more in depth as well, so go check us out!
If I missed anything in this guide, help me out and leave a comment. Happy hunting!!!