Well, I have looked at your other project with the knight (I will not use the p-word!) and I'm not sure wether you need this lesson, but here goes nothing:
Collision is a very important topic in computer games. The easiest way to do it is with square blocks. So, in skull hunt (like the name, btw) you could make 3 kinds of blocks. Those are all of the same size, it would be a good idea to pick a power of 2 for various reasons... I like 16x16, for example.
first one: ground, basically nothing, just a free place the pc can walk to.
second one: wall, this one is collidable (is that correct?). That means? ... The pc cannot walk here and most importantly, if the player tries it, the pc is:
a. stopped
b. put back to the last position, it COULD walk
The important thing about the wall-block is that it is absolutely solid. (That means collision happens from all sides). So for that nice labyrinth-look, you would want to make sure the graphics reflect that. The blocks should have an outside and an inside, in your graphics that outline, that marks the walking-area would be the outside, the bricks the inside. And then you'd have several blocks for different pieces of wall:
-a block that has a vertical outline on the left and a vertical one on the right-your basic vertikal wall
-a block that has a horizontal outline on the upper and one on the lower side-your basic horizontal wall
-four corners with adjacent vertical and horizontal outlines
-four end pieces (3 outlines each)
-and so on...
(And then you click your labyrinth together like a puzzle.)
third one: pickupablething, in this case the skull. Guess, you know how this goes...
That was a lot! I hope, I didn't tell you tons of stuff you already know. If you want to do me a favor in return, please download and play my game (or demo) and leave a comment!