Thanks for the feedback and taking the time to really try it!
Yeah, there is that bug...
It happens when you fall in the junction of two 45° "(0,1)-(1,1)-(1,0)" tiles.
What I believe happens is that you fall exactly on the junction vertex between two tiles... and the response pushes the the entity in the wrong direction... inserting it into a square whole tile, that in turn pushes it up, and again to the side until there is no more 45° tiles and it just pops up.
I'm working on that, the collisions code is a mess :lol:
Actually is really awful and hard coded, as I got it working in a day or two just to get by (before the game took shape, I thought it would be a small competition entry).
All entities, even round ones, have square collision shapes to test against each other (no phyisics response), and colliding with the world is just done using position and velocity ("a point" at the feet of actors and center of bullets) :oops:
http://forums.tigsource.com/index.php?topic=6637.0 here is an english post at tigsource forums, with a list of known bugs (just in case another pops in)
Good luck!
-Martín