This question follows a specific pattern of not constructive questions that have also already been asked and answered, and that are also based on opinions, which can lead to extended discussion, debate, or arguments, as defined by the close reason, which is listed beneath every closed post:
As it currently stands, this question is not a good fit for our Q&A format. We expect answers to be supported by facts, references, or specific expertise, but this question will likely solicit debate, arguments, polling, or extended discussion. If you feel that this question can be improved and possibly reopened, see the FAQ for guidance.
This question is similar to:
What language should I learn next, Java or C++?
Which is better, Java or C++?
On Programmers SE, the place where you should actually go to ask whiteboard questions, these questions are quickly closed because they don't solve a real problem. When looking at these types of questions after the smoke has cleared and everyone has moved on, it's never clear which langauge is actually better or which language one should learn next.
In fact, there's a blog post about this, called Gorilla vs Shark, that does a great job of explaining why these types of questions don't fit the Q&A format.
With that said, from reading your question, I see you mention that you've hit certain "pitfalls" in game development with certain languages. So instead of asking for a single, catch-all, polling explanation from each and every individual who drops by your question, you should instead think about each problem you're facing as a completely separate individual question.
For instance, if you're having trouble with games written in Java lagging, maybe ask how you can speed them up, showing what you've tried and what results you're seeing. They may not be perfect questions, but they'd be better than simply asking people to list all the similarities and differences between the two languages.
What's more, you may actually find a solution to the problem. If that solution is "Java sucks for game development, use C++", then that's great, but the answer could also be "Increase the heap size" or something that involves using the features of the existing language. Hope this helps!
As an aside, I saw in the comments, on your Stack Overflow question, that you asked why the question was not constructive; it seems it was not clear. Thus, you may be interested, as a new user, in weighing in on this proposal to make it clear what closed actually means, as it seems the close reason, from a user interface perspective, is easy for people to miss.