Code cleanup and minor fixes to Level 3

Levels/SlowTime.gd

@@ -1,17 +1,16 @@
 extends Node
 
-const END_VALUE = 1
-
 signal unfreeze
 
-var is_active = false
-var time_start
-var duration_ms
-var start_value
+const END_VALUE: int = 1
+
+var is_active: bool = false
+var time_start: int
+var duration_ms: int
+var start_value: float
 
 
-
-func start(duration = 1, strength = 0.9):
+func start(duration: int = 1, strength: float = 0.9):
     time_start = OS.get_ticks_msec()
     duration_ms = duration * 1000
     start_value = 1 - strength
@@ -19,7 +18,7 @@ func start(duration = 1, strength = 0.9):
     is_active = true
 
 
-func _process(delta):
+func _process(_delta: float) -> void:
     if is_active:
         var current_time = OS.get_ticks_msec() - time_start
         var value = circl_ease_in(current_time, start_value, END_VALUE, duration_ms)
@@ -28,7 +27,9 @@ func _process(delta):
             value = END_VALUE
             emit_signal('unfreeze')
         Engine.time_scale = value
-        
+    return
+
+
 func circl_ease_in(t, b, c, d):
-    t /=d
+    t /= d
     return -c * (sqrt(1 - t * t) - 1) + b