In AppGameKit, you can define your own collision shape, line by line and as many as you need. You can also grab a line to line intersection function, store the lines in an array, then use that as your own collision system. There are examples about, I can post one if you're stuck - but these would be for DBPro... with AppGameKit the collision line by line setup is a no brainer.
One cool thing about convex shapes made from connected straight lines, is you can very easily tell if a coordinate is inside it, or out.... just project a line between the sprite and a coordinate that you know is inside the shape (or outside, you just need to know which), and count how many of your lines intersect with that line. If the sprite is inside the shape there will be an even number of collisions, otherwise an odd number of collisions. It's pretty cool really how easy that is and how it works with even the most complex shapes.
The code is dark and full of errors