Here is the full list of all 24 Symmodance achievements.
Reach 100,000 total kills.
Get 50,000 kills with the Chronopiercer.
Get 50,000 kills with the Devastrixel.
Get 50,000 kills with the Electrend.
Get 50,000 kills with the Ionsight.
Kill the Beamcraft 100 times.
Kill the Shredclaw 100 times.
Kill the Voltbrute 100 times.
Successfully finish Miragora's Classic mode.
Last 30 minutes in Miragora's Endless mode.
Survive 10 minutes in Miragora's Hardcore mode.
Upgrade your platform to maximum level.
Survive 20 minutes in any mode without picking up any items.
Survive 20 minutes in any mode without picking up any weapons.
Survive 20 minutes in any mode with only 1 weapon.
Survive 20 minutes in any mode with only 2 weapons.
Survive 20 minutes in any mode with 3 identical weapons.
Kill the Spawnshock 100 times.
Kill the Glaciator 100 times.
Kill the Shardshooter 100 times.
Successfully finish Lyrastris's Classic mode.
Last 30 minutes in Lyrastris's Endless mode.
Survive 10 minutes in Lyrastris's Hardcore mode.
Get 50,000 kills with the Arcanevo.