On game two or three, go to the maze in the Black Castle. One screen left of the first maze screen will flicker if you carry an object in there meaning one thing, there's ANOTHER object in there. At the bottom center of this room is a closed off cubicle, use the bridge to get in there and you should pick up a "dot". Carry this to the screen just above the catacombs (one screen down and to the right of the Gold Castle) and be careful not to lose it as it's the same color as the outside ground. Drop it there and bring two other items onto the screen, run right through the line on the right side of the screen and witness the first ever Easter Egg.
Get Rid of the Bat
In games 2 and 3, the bat is the biggest pain in the @$$ we all know. He has a nasty habit of trading you a dragon for the sword. To stop him, I suggest the following ploy:
open the Gold Castle and leave the key high in the room. catch the bat. as long as he's not carrying a dragon, of course. take the bat back to the gold castle. wait for a couple of minutes,and you might see the bat shift the item it has in hand. let go of the bat. the fickle little $#!+ will gladly scoop up the gold key and fly off. If he flies up, up diagonally, or sideways, he cannot leave the castle. You are now bat free and ready to deal only with those pesky Dragons.
Rapidly turn the game off and on until you get a start screen with other items/dragons/bat on the screen. Start a game at any level and the black "Barriers" may have moved to where you can get around them using the entrances at the top and bottom of the screen. This doesn't help you with the game much, but hey, just the chance to do it is worth the work.
The bridge can be used to take shortcuts across screens. In games 2 and 3, you can place the bridge in the "red room" (two screens down from the white castle) and reappear ABOVE the castle. DO NOT do this in the room below the gold castle, because for some reason you get stuck. Experiment in the blue maze for other shortcuts!
Hit SELECT as soon as you finish the game and you'll hear the ending fanfare play really slow.
Walk on the Title Screen
Start a game then press SELECT to get the game selection screen (with the number in the center). Pull down and your character will appear. (You can't do anything but move around the screen however.)