After spending some time with the development of a 2D game for PC or maybe other platforms I had time to test out some engines that we have access to for free at home or with student licences in school.
For rapid prototyping the Game Maker is the first choice but it has problems with complex mechanics and collusion detection.
Working with Sprites and only 2D objects makes the use of an engine like Unity3D or even the UDK more tedious than helpful because these engines are designed for 3D gameplay and 3D meshes. To tell them otherwise via code is a lot of work and the result is not always desirable. 2.5D on the other hand is more easy to accomplish because the engine already knows how to handle 3D meshes and the "2D gameplay" is possible with some camera tricks.
Using an 2D engine like Torque2D is the better choice for Sprites, 2D objects and 2D gameplay. I am just starting to work with it so I will hold my praises for the moment, maybe it is easy, maybe not...
As for scripting languages most engines today use some kind of c++ related syntax and operators so the switch between different engines is not so difficult, in some cases the code is even transferable between them if not too much engine specific code is being used.