How many bosses are there in Metroid for NES?
3
2
2
2
2
1
2
1
2
1
4
2
3
1
4
2
3
1
4
2
3
1
4
2
3
1
4
2
3
1
4
2
3
1
4
2
3
1
4
2
3
1
4
2
3
1
4
2
3
1
4
2
3
1
4
2
3
1
4
2
3
1
4
2
5
3
1
4
5
3
1
4
5
0
3
1
4
5
0
3
1
4
5
6
3
0
4
5
6
3
8
4
5
0
6
3
8
7
5
0
6
8
7
5
6
8
0
7
5
6
8
7
5
0
6
8
7
5
0
6
8
7
5
6
8
10
0
7
5
6
8
10
7
5
0
6
8
10
7
5
6
8
10
7
5
6
8
10
7
5
9
6
8
10
7
5
9
6
8
10
7
5
9
6
8
10
7
9
6
8
10
7
9
6
8
10
7
9
6
8
10
7
9
6
8
10
7
13
9
11
8
10
7
13
9
11
10
7
13
9