Easter Egg Number 1
In Act 3: Level 4 (the garage), there is an Easter Egg featuring members of Max Payne's production team and some surprises. After the opening animation ends, take out the four guys that the car has dropped off. Now, before entering the garageon the right, face the garage and look just to the
right of the opening. There are 3 barrels (one, and then two on top of each other), and an A/C unit coming out of the wall. Jump >from one to another to reach the roof of the garage. You will now be facing a little shack on the roof, with a door-shaped section painted slightly lighter than the rest -- shoot this with any weapon, and it will fall away, leading to a room with a small
grating on the floor. Stand on the grate, and you will fall into a room with a dead hostage, a sniper rifle and ammo, and a radio that plays a conversation between members of the production team with a bit of humor at the end.
Easter Egg Number 2
In the rooftop chase sequence there's a room you can get to that has a poster of Soldier Of Fortune II and some other useful goodies.
Easter Egg Number 3
In Chapter 3 when you start on the roof of the multi-storey car park you can jump on the barrels and then onto the roof near the exit ramp. If you shoot the peculiar looking metal wall you'll see it collapse. Then go through the opening, drop through a nearby vent in the floor and you'll end up in a small room. You'll find a sniper rifle and some ammo and a radio. "Use" the radio for some laughs.
Easter Egg Number 4
When you walk in on the bank robbery, you can shoot the wailing siren to stop it. Do this and Max will thank you.
Easter Egg Number 5
When you find the piano on the manor level, if you "use" it Max will play the title theme. Shoot the lid support out to drop the lid and then try playing the piano again.
Easter Egg Number 6
When you find the drum kit in the Ragna Rock bar, "use" it to play some beats. You can also get the guitar on the floor to squeal and if you "use" the stage microphones Max will say: "Karaoke was never my thing".