If you enjoy writing in Pascal then end of discussion. Write in Pascal.

C++ greatest strength is its history. It's been used in so many years and has become the de facto standard in game development. This means that many great libraries/frameworks for rendering, collision, physics etc. etc. are written in C++ or at least have C++ headers. Besides this massive library I can't see any reason C++ is better than other languages for writing games. Some might mention managed versus unmanaged languages but unless you're writing a triple A title you don't need the control C++ (and Pascal) offers you. However IMO C++ is a hard language to write in. It's easy to learn the syntax etc. but even when you have a good understanding of the language bugs easily creep into your code. IMO Pascal is just easier to write than C++. So unless you need some external libraries and you don't have Pascal headers (or want to write yourself) Pascal should be a fine language.

But I agree with Stoney. There's too many engines written in Pascal compared to the number of users (at least on this forum). Further more there doesn't seem to be any clear advantage to choose one library over the other. If all those people are writing their own engines for learning purposes then fine, but if they want to advertise the use of Pascal as a game development language it would be better if they joined forces and created one über-engine comparable to the best engines written for other more popular languages.
Also most engines seems to stop when they can render sprites and do some basic collision handling etc. If you really want to show how great Pascal is for creating games it would help if you could show an engine that through ~5 lines of code can load a 3D world, render it in high quality and move around with a first person controller that interacts physically realistic with the environment. And it should be easy to implement and add moving entities in the world e.g. by offering modern AI technologies like efficient path finding, behaviour trees, heat maps etc. Unless someone could offer an engine like that I wont consider Pascal for more than simple hobby game projects.

I did some experimentation with Pascal for .NET (oxygene / Delphi Prism) and Unity 3D and I must admit that IMO it is the most interresting use of Pascal in game development I've experienced in many years. If I were to write a game for commercial use I would choose something like Unity 3D because it offers so much more than the engines written by one or two persons in Pascal. But at least I can use Pascal with Unity if I wish to do so.