Yup, but you can’t sell the game engine, so if you want to sell your game you have to be a bit sneaky (but still legally). But I am a fan of open source software so I shan’t tell you unless you ask specifically.
As to pointers how to do that run a search for “export game to runtime”
yes you can
A common misunderstanding of the GPL.
You can sell your game!
You can even sell blender!
Here is my example of what you can do with blender:
GPL doesn’t state you can’t sell. You can (and probably should)!
The problem is, when you export your game as an .exe file all your cotent is under the GPL. That means people can use your work for what ever they want.
Thats why I wouldn’t export it as an exe. Instead I would provide the blenderplayer and your blendfile seperately. This way you make sure all the rights of your blendfile stay yours!
In my opinion GPL is the preferred when possible (I understand this isn’t always possible) way to publish.
We all benefit from Blender, because it falls under GPL. So if you have any sort of success, i hope you think of where your success is build upon and give something back. That doesn’t mean you have to share everything you’ve got though. So yes GPL has downsides, but at least consider publishing parts of your development under GPL, to give back to the community in a contributing manner.
We ask so much form the Blender/BGE developers, but what do we give them back? 
A good meet in the middle might be:
First try to get your investment back (with the preferred profit), and when this has been accomplished (or that it is evident that you won’t accomplish this),
then consider giving (parts) back to the general public under GPL.
That way we can learn and benefit from each other and keep heading forward.
GPL (sort of) ensures progress.
Nope.
When you release anything (be it code or content) under a certain license YOU specify the terms of the release. If you make it available under terms that allow its re-use (even commercial re-use) then people will and SHOULD re-use it. That’s the very fundamental idea of sharing, using, and re-using.
For instance, if you create a game resource (say a character or something more complicated like a scene/level) and release it under Attribution (CC-A) then others are free to re-use it to make a derivative (say a 2nd level) and even charge for that PROVIDED that they ATTRIBUTE your credit.
Thats why I wouldn’t export it as an exe. Instead I would provide the blenderplayer and your blendfile seperately. This way you make sure all the rights of your blendfile stay yours!
See monster’s commend above.
You seem to be confusing licenses with other issues.
As the saying goes for software (and lately for content) licenses you don’t understand it unless it makes you dizzy! 
Well… thats not true blendercomp!
See this Link
Blender and the BlenderPlayer fall under the GNU General Public License. Blend files are copyrighted to their respected owners and do not fall under the GPL as long as they are not packed in the BlenderPlayer. If a user does not want the blend files to fall under the GPL, it is recommended not to use the “Save Game as Runtime” feature. To put it another way, the user must keep the blend files and the BlenderPlayer in separate files. More information can be found at http://www.blender.org/education-help/faq/gpl-for-artists/. (Blender 2.6 now has a run game from file actuator.)
You have all rights of your blendfiles, as long you don’t pack them into the blenderplayer.exe! And when you export your game as an .exe file you are packing your blendfiles into the blenderplayer, and all your files go gpl!
ndee thanx for sharing the link.
Like I said, you are considering two dimensions at the same time. It’s not that you cannot do it, it’s just that these are different entities and should be considered differently. Once you’ve referenced that page, please consider the following stated in the beginning of said article:
“Games created in Blender (.blend files) are program output and therefore not covered by the GPL. You can consider them your property, and license or sell them freely.”
Thus, the content created by using some GPL code is YOUR property and you can license it at will.
As it is stated there, the executable is, technically speaking, code. Consequently, the same GPL freedoms apply as the ones hold for the code originally used to create it. This is meant to promote copy-left and disallow copy-right.
What you’re saying covers the technicalities of distributing a creation made with Blender. There’s a very subtle conceptual difference in there.
I know we’re getting a bit off topic here, but someone that fully understands the whole licensing details with the GE needs to make a video about it and pop it on youtube. I have seen this debate quite a few times now, and the debates are making it more confusing. Linking the debate to the video would just make things easier. I am now so confused by the whole thing.
I would love to look into the matter more and make a video informing people exactly what the deal with this is, but I dont really have the time to do so at the moment.
As some have guided elsewhere on these forums already. You can have the blenderplayer just load another blend file as soon as it starts up that consists your game and it’s content and thus you own the game.
Yep… I just stated out what happens if you pack the file into the blenderplayer. The way you mention it the main blendfile stays seperate from the blenderplayer.
And of course I know when you create something with blender that all rights belong to you! But you have to be carefull with packing files into the blenderplayer.exe
Thats all
Ofcourse it’s always good being careful! 
There got to be a like button around here
Back on topic. In my opinion the Blender Game Engine itself is somewhat poor from a programmers perspective, but is very good from an workflow perspective.
The Python API is very light so you will have a hard time modifying, or even creating objects in code. If you don’t plan on doing much more than moving object positions etc around in code then you are good to go.
Bbplayer is awsome! But as far as I know, it is BGE actually. Just separated from the (decoded) blend file to prevent your game from becoming open source licensed. Good for commercial projects.
But the question was, how good is the Blender game engine. And bpplayer is/uses Blender game enige.
The BGE’s gotta be one of the best game engines in the world currently, mainly because of its workflow. The ability to easily go from modeling and programming to running the game is a unique, very useful one. While the BGE does miss some features like a dedicated particle system or the ability to merge and separate meshes in-game, it exceeds because of its usability.
I was going to try out Unity or jME3, but I’m just too used to the BGE. Some people might be unhappy that it doesn’t have any mobile capabilities, but the games I want to make wouldn’t be good on mobile devices (which currently are basically for casual games). I want to make ‘drag-out, sit-down, devote-days-to-this’ kinds of games, and the BGE is more than up to the challenge. In addition, I’m learning more about getting around the limits of the BGE to achieve more and execute more. I think the longer I use the BGE, the more efficient the games I’ll make.
I think taht a good way to distribute the games is with a loader or something, first encript the .blend in order to not let other users modify the file, and then have a loader that can read the encripted version. But for that you would need to write something like the blenderplayer I guess, i really not shure about it, and Im sorry if Im mistaken. But one thing I know for shure, if you plan in sell a blender game, even if you have your rights protected with the .blend everyone ll be abble to open your .blend on blender and play your game for free if its not encripted.
I agree with solar lune, but for me BGE is weak compared to other engines, specially because it is slow in some aspects and lack on features, but its really amazing that with a little more knowledge it became mutch more powerful, usually people complain about BGE but those users hardly know about the game creation.
I have to agree with SolarLune! In my opinion the BGE is a great Engine! Of course not one of the best(imo) performance wise, but as already mentioned, the workflow is the best you can get! I love the speed you have in testing things. Just create your model… connect a few bricks… write some lines of code if needed and boom you have something workable!
This is just great! If you don’t have some tools you can even expand blender itself for those needs. Recently I have created my own simple Level Editor! Its great!
My most concern is the lack of interest from the blender foundation! I know there are some developers that are working on the bge! But there is not direction/roadmap from the blender foundation. Thats sad, and I hope Ton will change his mind in the future!
I agree, the priority of the BGE development is low. But then again, it isn’t just the Blender Foundation who is responsible, we as a community are. So strap on those coding boots, through on your compiling hat, and go for it!
But to answer the original question once more:
consider we are all here on the BGE forum active, not because we dislike the BGE