-To get the level select, use the Konami code (up, up, down, down, left, right, left, right, B, A) at the main menu. In the final version, this code unlocks expert difficulty and gives you more lives.

-The prototype's copyright screen can change depending on what region of console is used:

Japanese	USA	Europe

From what I've checked, this is the only regional difference the prototype has, none of the other changes the final versions made have been implemented yet.

-The prototype is missing many sound effects, with many more added for the final version.

-The prototype gives you 4 continues, in the final, you only get 2.

- It takes Eric longer to charge his high jump in the proto, in the final he can do it nearly instantly.

-In the prototype, Eric's high jump has him move to the left or right at the top of his jump. In the final, he goes straight up during his high jump.

-If you pause the game in the prototype, there's no on-screen message. The final added the word "PAUSE" for whenever the game is paused.

-Expert mode hasn't been implemented in the prototype version yet. In the final version, you can unlock it by beating the game on normal, or using the Konami code. In the prototype, the Konami code unlocks the level select.

-The prototype lets you use the second controller. Press up and down with the A button goes either forward or backward a stage. Pressing the B button gives you full life and 99 crystals.

-Whenever you power your characters's weapon to the fullest in the prototype, a classic Castlevania tune will start playing until you get to the next stage, or take damage. In the final, you can only get this to happen by using a cheat code in the sound test first.

-When you take damage in the prototype, you don't lose it from the life bar immediately. In the final, the bars get removed immediately.

-When collecting the orb after beating a boss, your character will freeze immediately in the prototype. In the final, you can jump and attack for a few seconds before they freeze.

-There is some kind of glitch in the prototype which lets you damage enemies just by touching them. If you take damage, then walk into an enemy immediately afterwards, it can harm them -the easiest way to see this is with the zombies in stage 1-2.

-When John does in the prototype, he turns into a skeleton as he falls, but when his body hits the ground, the skeleton sprite becomes a glitchy mess:

Prototype	Final

The previous prototype has a similar death animation, but without the glitched sprite. In the final version, John will flash and vanish upon death.

-In the prototype, some enemies have more health than they do in the final version, such as the minotaurs.

-Use the level select to get to stage 2's boss, and you'll die immediately due to there being no hitbox on the platform you're meant to land on. When you respawn, you end up here:

Prototype

The water level will drop down, and you are in an alternate version of stage 2-6 which wouldn't be seen otherwise. This stage can be beaten, and has several candles in it, but no enemies. The ship background can be seen in the final game.

-Stage 6 is not present in the prototype, but there is an early version of the final boss room. You'll have to use the level select to enter it (stage number 48).

Prototype	Final
The background is incomplete, with no background, and garbage sprites for the floor and sides. But Dracula will appear, and can be fought without any problems. He has all the forms and attacks he has in the final version, but he's much weaker -each form only takes around 3 hits to defeat.

Prototype	Final
The colors of the flames Dracula's final form uses have glitched colors in the prototype. He only seems to use the flame attack when he's pink in the prototype, and red in the final. In the prototype, Dracula will turn gray and die once hit enough times. In the final, when he turns gray, he has an additional attack where he jumps around, and sends bones everywhere when hit.

The prototype has this battle as being part of stage 4-10. In the final version, it's stage 6-11. When Dracula is beaten in the prototype, it'll take you back to the first stage.