It all depends on your list of demands. Delphix is probably the most easiest to learn. However, it's not the fastest of the three though. If you're looking for advanced rendering features like alphablending, you're better of with asphyre or xcess. As for as collisions go, I'm not entirely sure about asphyre, but undelphix and xcess both have inbuild routines, so you don't have to write those yourself. A disadvantage of asphyre or xcess might be the requirement of additional dll files. They also require you to credit the 'engine' in the endproduct.

For a game like Raptor, all three are quite capable of producing the game.