A bit late. Here's a little update of some game mechanics and assets.
After several playtests I didn't find any critical flaws so I'll start to work on v0.12 major update from this moment to bring a lot of new things into gameplay.
See you next time!

DETAILED LIST:

• Props on W1 were redrawn
• Rare chests may drop more upgrades on lack of mask
• Some assets on W2 are destructible now
• Decreased safe zones of voidwalking on W6
• Void Grue became faster
• Shorter invincibility time after mask loss. 0.66 seconds -> 0.4 seconds
• Decreased chance of item drop from 12.5% to 7.7%
• Energy penalty now gradually rising for every 20% of energy instead of 100%
• Different counters for masks and items on HUD.
• Color change on enemies' HUD counter is more smooth
• Lacuna's attacks are destroyed on its death

[MASK REWORKS]

Elenor:

• Mask was renamed. Previous name: Leonor.

Leech Seed:
• Homing prioritizes enemy next to cursor
• Gives 1% soul energy per damage tick
• Faster starting projectile speed, projectile loses speed over time
• Decreased tick time from 0.5 second to 0.4
• Decreased attack damage

Wrath of Trees:
• Affects 4 enemies instead of 5

Taika:

Magic Dart:
• Better homing
• Increased projectile's acceleration and decreased starting speed
• Increased attack speed
• Slightly decreased attack damage

Arcane Orb:
• Energy affects number of damaged enemies and radius instead of damage output
• Projectile's speed slightly increased

Avilora:

Comet:
• Utterly reworked Comet's mechanics

Delshad:

• All Delshad's attacks ignore enemies' armor

Sudden Cardiac Arrest:
• Deals 20% of maximum HP instead of 10% of current HP
• It's now area of effect skill
• Increased cooldown

Massive Heart Attack:
• Deals 10 + 30% of missing HP instead of 50 + 50% of missing HP
• Decreased radius of effect from 256px to 160px
• Decreased cooldown and invincibility

Hurtbeat:
• Deals 10% of current HP instead of 5% of maximum HP

Zazzar:

Ball Lightning:
• Drastically decreased cooldown and invincibility time

Ersnio:

Lock-on:
• New visual effect and animation

Otto:

Mimicry:
• Copied melee attacks were added. Though not all attacks were implemented yet.

Phantom Army:
• Decreased number of copies from 6 to 3.

[ITEM REWORKS]

• Libra: Gives random damage bonus for number of Critical Hit Chance upgrades instead of overall critical chance
• Swapped effects of Tooth and Sting artifacts