level upgrade step

web/src/state/Root.ts

@@ -16,15 +16,24 @@ export class Root {
     public numberNotationName: keyof typeof Presets = 'Standard';
     public numberNotation: Notation = Presets.Standard;
 
+    public upgradeStep: number | 'max' = 1;
+
     constructor() {
         this.copyGame();
         this.setNumberNotation();
 
         makeAutoObservable(this);
     }
-    
+
     public setLastGameTime(value: number) {
-      this.lastGameTime = value;
+        this.lastGameTime = value;
+    }
+
+    public setUpgradeStep(value: number | 'max') {
+        if (typeof (value) === 'number')
+            this.upgradeStep = Math.min(value, 1000);
+        else
+            this.upgradeStep = value;
     }
 
     public tick(deltaTime: number): void {