The player experience didn't quite live up to the term "cozy" considering the difficulty.
Therefore, the attributes of buildings and units were changed as much as possible to make the game feel more fair for every type of player.

Three new difficulty levels have been introduced: Cozy, Default and Survival. Apart from balancing, these give a change to the health points and damage of units.

Difficulties:

• Cozy (Preset): -20% on units, +20% on buildings and turrets
  
• Default: 0% change
  
• Survival: +20% on units, -20% on buildings and turrets

Moreover the health points of units and buildings have generally been doubled.
The damage of units has been roughly halved.
As a result, neither buildings nor units should no longer feel like paper.

The following values have been changed:

Tanks:

• +100% HP
  
• -50% damage

Aircraft units have been made slightly stronger to compensate the deficit in health points of buildings.

Zeppelins:

• +60% HP
  
• +10% damage

Airplanes:

• +40% HP
  
• +40% damage

The boss tank did too much damage, but should remain tanky. Its task is to break your base building, not your defense.

Boss Tank:

• -25% damage

Turrets:

• Rocket Turrets: Reduce Price Costs slightly to make them more valuable
  
• Machine Turrets: 100/200/300 -> 200/400/600 HP
  
• Rocket Turrets: 60/90/120 -> 100/200/300 HP
  
• Rocket-Gun: 15/20/40 -> 20/40/80 Damage
  
• Air-Rocket-Gun: 12/18/34 -> 15/30/45 Damage
  
• Machine Gun Turret: 18/32/64 -> 21/35/67 Damage
  
• +50% necessary xp amount for turret upgrades

Economy:

• Houses: 75/250/500 -> 150/350/600 HP
  
• Houses: +10/+10/+10 Gold income
  
• Factories: 100/160/300 -> 200/400/700 HP
  
• Factories: +5/+10/+20 Building Material
  
• Base Building: 500 -> 800 HP

If you feel like the game should be more easy, consider to post inside the community hub.
The difficulty factor can be adjusted easily on the developer side.
Enjoy!