Ninja Gaiden being a NES game should be considered easy right? Well.. it is, that is until you reach stage 5-1 then all hell breaks loose.
Timestamps
Stage 1-1: 00:00
Stage 1-2 (Barbarian): 01:18
Stage 2-1: 03:03
Stage 2-2: 04:21
Stage 2-3 (Bomberhead): 05:45
Stage 3-1: 08:36
Stage 3-2: 09:21
Stage 3-3 (Basaquer): 10:33
Stage 4-1: 16:02
Stage 4-2: 17:41
Stage 4-3: 19:12
Stage 4-4 (Kelbeross): 20:43
Stage 5-1: 23:00
Stage 5-2: 24:13
Stage 5-3: 25:42
Stage 5-4 (Malth): 28:00
Stage 6-1: 28:43
Stage 6-2: 29:20
Stage 6-3: 30:59
Stage 6-3 (Devil Mask): 33:57
Stage 6-4 (Jacquoi): 35:36
Stage 6-5 (Demon): 37:54
Timestamps
Stage 1-1: 00:00
Stage 1-2 (Barbarian): 01:18
Stage 2-1: 03:03
Stage 2-2: 04:21
Stage 2-3 (Bomberhead): 05:45
Stage 3-1: 08:36
Stage 3-2: 09:21
Stage 3-3 (Basaquer): 10:33
Stage 4-1: 16:02
Stage 4-2: 17:41
Stage 4-3: 19:12
Stage 4-4 (Kelbeross): 20:43
Stage 5-1: 23:00
Stage 5-2: 24:13
Stage 5-3: 25:42
Stage 5-4 (Malth): 28:00
Stage 6-1: 28:43
Stage 6-2: 29:20
Stage 6-3: 30:59
Stage 6-3 (Devil Mask): 33:57
Stage 6-4 (Jacquoi): 35:36
Stage 6-5 (Demon): 37:54