Yep, give it to Charity.
You're handling tile movement with the following events:
<img src="http://i.imgur.com/L22dErC.png" border="0">
You're moving the selected tile 1 pixel per tick horizontally/vertically in the appropriate direction while its position does not equal its Destination. This method is problematic for moving/stopping tiles for 2 reasons:
- It's framerate dependant
- You would need to use inefficient methods to increase the speed
If you were to continue with this movement method, the easiest way to have the tiles move faster would be to repeat these events multiple times in a loop. For example, if you looped through the above events 3 times per tick, each tile would move 3 pixels per tick. There are other more efficient methods for movement that are also frame rate independent. Here's one method: capx
There are even better ways to handle this type of movement, but other parts of your game would need to be reworked. Another option would be to use rexrainbow's "moveto" behavior. It makes movement like this very easy, however it's always good to know how to do it yourself. I'd also recommend looking into Ashley's tutorial on frame rate independence and dt.