At first I thought you were suggesting putting an illusory Matt Colville in the maze as a jump-scare.
These are fun ideas, but each fantastic idea that you add is another logical step the PCs need to (successfully) take to 1) be able to solve them, and 2) reach the end of the maze.
Look at it this way: you're starting with a maze. If it's complex, it's already enough to fill a game session, with X players who have the map and one player who has to trust they're telling her to go in the right direction. Next, the maze is magical, which means that most real-world assumptions are out the window. If you want to confuse someone, make sure most of that person's assumptions have a chance of being invalid - that's what a magical maze does. Now we're at the cool ideas: the darkness, magical fire, the cannon. If the players are veterans, they might still have hope for the maze. I expect any casual players to be nonplussed, so you can still go crazy, but as GM, you're going to need to offer a serious helping hand if you want the players and the characters to have a shot of getting through.