error CS0118: 'Player' is a 'namespace' but a 'type' was expected

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using Player ;

namespace Player {

public class MonoBehaviour {

	Player pl1 = new Player ();
	GameObject [] pauseObjects;
	GameObject [] finishObjects;
	//player Player;

void OnTriggerEnter2D(Collider2D other){

	if(other.gameObject.tag == "Player"){
		other.gameObject.GetComponent<Player>().alive = false;
		Time.timeScale = 0;	}
}

void Start () {
	Time.timeScale = 1;

	pauseObjects = GameObject.FindGameObjectsWithTag("ShowOnPause");			//gets all objects with tag ShowOnPause
	finishObjects = GameObject.FindGameObjectsWithTag("ShowOnFinish");			//gets all objects with tag ShowOnFinish

	hidePaused();
	hideFinished();

	//Checks to make sure MainLevel is the loaded level
	if(Application.loadedLevelName == "MainLevel")
		playerController = GameObject.FindGameObjectWithTag("Player").GetComponent<Player>();
}

void Update () {

	if(Input.GetKeyDown(KeyCode.P))
	{
		if(Time.timeScale == 1 && player.alive == true)
		{
			Time.timeScale = 0;
			showPaused();
		} else if (Time.timeScale == 0 && player.alive == true){
			Time.timeScale = 1;
			hidePaused();
		}
	}

}

public void Reload(){
	Application.LoadLevel(Application.loadedLevel);
}

public void pauseControl(){
	if(Time.timeScale == 1)
	{
		Time.timeScale = 0;
		showPaused();
	} else if (Time.timeScale == 0){
		Time.timeScale = 1;
		hidePaused();
	}
}

public void showPaused(){
	foreach(GameObject g in pauseObjects){
		g.SetActive(true);
	}
}

//hides objects with ShowOnPause tag
public void hidePaused(){
	foreach(GameObject g in pauseObjects){
		g.SetActive(false);
	}
}

//shows objects with ShowOnFinish tag
public void showFinished(){
	foreach(GameObject g in finishObjects){
		g.SetActive(true);
	}
}

//hides objects with ShowOnFinish tag
public void hideFinished(){
	foreach(GameObject g in finishObjects){
		g.SetActive(false);
	}
}

//loads inputted level
public void LoadLevel(string level){
	Application.LoadLevel(level);
}

}

}

The error is in using Player, namespace Player and public class MonoBehaviour:

using System.Collections; 
using System.Collections.Generic; 
using UnityEngine; 
using Player ;

namespace Player {

     public class MonoBehaviour {

It should be:

using System.Collections; 
using System.Collections.Generic; 
using UnityEngine; 

public class Player : MonoBehaviour {

Also don’t forget to remove the extra bracket at the end.

This is wrong:

public class MonoBehaviour {

It should be

public Player : Monobehaviour {

You are trying to instance there a class called MonoBehaviour, which cannot be done as Unity already implements it. You forgot to name your class properly and make it inherit MonoBehaviour.

Also you are setting Player as the namespace. Namespaces are not class names. I imagine your intention was to name you class, so change as I stated, and remove the namespace clause and its brackets.

If your intention was indeed to create a Player namespace, you still need to name the class properly.