game: add rat enemy

scenes/enemies/enemy_bat.tscn

@@ -0,0 +1,24 @@
+[gd_scene load_steps=4 format=3 uid="uid://du4t4vydra4rm"]
+
+[ext_resource type="PackedScene" uid="uid://b7vq8xspnlyeu" path="res://scenes/enemies/enemy_base.tscn" id="1_4r40l"]
+[ext_resource type="Script" uid="uid://bfhmjpjwdh25o" path="res://scenes/enemies/enemy_bat.gd" id="2_1jj4k"]
+[ext_resource type="Texture2D" uid="uid://chtjfq3bmonhj" path="res://assets/sprites/small_bat.png" id="2_608ut"]
+
+[node name="EnemyBat" instance=ExtResource("1_4r40l")]
+collision_mask = 2
+script = ExtResource("2_1jj4k")
+move_speed = 175.0
+max_health = 6.0
+default_contact_damage = 5.0
+target_distance = 2.0
+xp_dropped = 8.0
+
+[node name="Sprite2D" parent="." index="0"]
+texture = ExtResource("2_608ut")
+
+[node name="TargetCast" parent="." index="2"]
+collision_mask = 0
+collide_with_bodies = false
+
+[node name="ShapeCast2D" parent="." index="6"]
+visible = false