diff --git a/src/const/world/difficulty.ts b/src/const/world/difficulty.ts
index e2ddf392..758f8be1 100644
--- a/src/const/world/difficulty.ts
+++ b/src/const/world/difficulty.ts
@@ -8,12 +8,12 @@ export const DIFFICULTY = {
   PLAYER_HEALTH_GROWTH: 0.4, // Growth health by upgrade (Quadratic)
   PLAYER_HEALTH_EXPERIENCE_TO_UPGRADE: 80, // Experience need to upgrade health
   PLAYER_SPEED: 90, // Movement speed
-  PLAYER_SPEED_GROWTH: 0.04, // Growth speed by upgrade (Quadratic)
-  PLAYER_SPEED_EXPERIENCE_TO_UPGRADE: 60, // Experience need to upgrade speed
+  PLAYER_SPEED_GROWTH: 0.0556, // Growth speed by upgrade (Linear)
+  PLAYER_SPEED_EXPERIENCE_TO_UPGRADE: 80, // Experience need to upgrade speed
   PLAYER_STAMINA: 100, // Stamina
   PLAYER_STAMINA_GROWTH: 0.2, // Growth stamina by upgrade (Quadratic)
   PLAYER_STAMINA_EXPERIENCE_TO_UPGRADE: 60, //  Experience need to upgrade stamina
-  PLAYER_EXPERIENCE_TO_UPGRADE_GROWTH: 0.75, // Growth experience need to upgrade (Quadratic)
+  PLAYER_EXPERIENCE_TO_UPGRADE_GROWTH: 0.8, // Growth experience need to upgrade (Quadratic)
 
   /**
    * Assistant
@@ -23,7 +23,7 @@ export const DIFFICULTY = {
   ASSISTANT_ATTACK_SPEED: 500, // Attack speed
   ASSISTANT_ATTACK_DAMAGE: 15, // Attack damage
   ASSISTANT_ATTACK_DAMAGE_GROWTH: 0.5, // Damage growth by upgrade level (Quadratic)
-  ASSISTANT_ATTACK_DAMAGE_EXPERIENCE_TO_UPGRADE: 60, // Experience need to upgrade attack damage
+  ASSISTANT_ATTACK_DAMAGE_EXPERIENCE_TO_UPGRADE: 70, // Experience need to upgrade attack damage
   ASSISTANT_ATTACK_DISTANCE: 70, // Attack distance
   ASSISTANT_ATTACK_DISTANCE_GROWTH: 0.15, // Attack distance growth by upgrade level (Quadratic)
   ASSISTANT_ATTACK_DISTANCE_EXPERIENCE_TO_UPGRADE: 40, // Experience need to upgrade attack distance
diff --git a/src/game/scenes/world/entities/player.ts b/src/game/scenes/world/entities/player.ts
index f28037ef..fe49c8cc 100644
--- a/src/game/scenes/world/entities/player.ts
+++ b/src/game/scenes/world/entities/player.ts
@@ -389,34 +389,33 @@ export class Player extends Sprite implements IPlayer {
     });
   }
 
-  private getUpgradeNextValue(type: PlayerSkill, level?: number): number {
-    const nextLevel = level ?? this.upgradeLevel[type] + 1;
-
+  static GetUpgradeNextValue(type: PlayerSkill, level: number): number {
     switch (type) {
       case PlayerSkill.MAX_HEALTH: {
         return progressionQuadratic({
           defaultValue: DIFFICULTY.PLAYER_HEALTH,
           scale: DIFFICULTY.PLAYER_HEALTH_GROWTH,
-          level: nextLevel,
+          level,
           roundTo: 10,
         });
       }
       case PlayerSkill.SPEED: {
-        return progressionQuadratic({
+        return progressionLinear({
           defaultValue: DIFFICULTY.PLAYER_SPEED,
           scale: DIFFICULTY.PLAYER_SPEED_GROWTH,
-          level: nextLevel,
+          level,
+          roundTo: 1,
         });
       }
       case PlayerSkill.STAMINA: {
         return progressionQuadratic({
           defaultValue: DIFFICULTY.PLAYER_STAMINA,
           scale: DIFFICULTY.PLAYER_STAMINA_GROWTH,
-          level: nextLevel,
+          level,
         });
       }
       default: {
-        return nextLevel;
+        return level;
       }
     }
   }
@@ -443,7 +442,7 @@ export class Player extends Sprite implements IPlayer {
   }
 
   private setSkillUpgrade(type: PlayerSkill, level: number) {
-    const nextValue = this.getUpgradeNextValue(type, level);
+    const nextValue = Player.GetUpgradeNextValue(type, level);
 
     switch (type) {
       case PlayerSkill.MAX_HEALTH: {