[
            {"id": "grass", "type": "empty"},
            {"id": "path", "type": "path", "path": {"ground": true, "air": true}},
            {"id": "spawn", "type": "spawn", "path": {"ground": true, "air": true},
             "spawn": {
                "loop": true, "loop_hp_scale": 0.2,
                "waves": [
                    {"enemy_id": "grunt", "count": 10, "interval": 1.0, "hp_mult": 1.0},
                    {"enemy_id": "grunt", "count": 15, "interval": 0.8, "hp_mult": 1.2},
                    {"enemy_id": "tank", "count": 5, "interval": 2.0, "hp_mult": 1.5}
                ]
             }},
            {"id": "base", "type": "base", "path": {"ground": true, "air": true}}
        ]