Some time ago I mentioned a technique for defeating one of the bosses in Blaster Master that involved a maneuver known as 'strafing' (even though it's not really strafing). Strafing in this case means firing your weaponry in one direction while moving in another. Normally, this is impossible in Blaster Master.

Unless...

If you first fire a Grenade, and then hold down the A button, Jason will stay facing the same direction, no matter what you push on the Cross Pad. Observe:

Which is incredibly useful for flying enemies that attack in irregular patterns... and certain giant crabs.

The only downside is that while you're doing this you can't fire your grenades, but if you keep your gun powered up, that's not too much of an issue.