I'm going to keep this short. I want to make a game that is somewhat similar to Dune 2000. I bet you all know of some engines and language I should use to create a top-down RTS similar to Dune. I'd like to keep the game to 2D isometric but I might try 3D isometric if it isn't as challenging as 2D.

We might be able to help better with more information about what you know, what is your budget(if any) and what have you used and done in the past.

For 2d, GameMaker tends to make things easier. For 3d, Unity makes things easier. But, they both have a bit of learning curve to learn the software. But then, if you code it yourself, you'll have an even bigger learning curve to learn how to code. Then, this all assumes you don't know any programming languages, etc...

I have very basic knowledge of C#, but I just need someone to point me in the direction of what to use, I'll gladly learn that language. I have used Unity3D for a few months, but just to make a third-person RPG based off of "BurgZergArcade"'s tutorial. I have also used GameMaker in or around 2008, I tried it again recently and was somewhat uninterested. Even though I have a job, I have little disposable income; so free is always better. All I need to know is: What engine and language should I use for a 2D-topdown or isometric RTS?

Like I said, it depends on you and what you know. Since Unity and Gamemaker are generally the easiest options, and you've used both, then it depends on whether you need 2d or 3d. Since you mention the price of free, Unity will be better, because the free version of Gamemaker has more limitations, and though Free Unity has limitations, they don't get in the way like some of the ones that GameMaker has.

In any case, both of these engines could handle such a game.

I'm still toying around with Unity and C#, it's not possible to do 2D isometric in Unity, is it?

Yes it is possible. The isometric viewpoint with real 2d graphics is simply the pixel art itself. But if you use Unity, you may be better of going 3d, and keeping the camera as an ortho camera at the 45 degree angle to get the viewpoint right, and then the gameplay you can keep onto that single plane. This way, you get the nice 2d gameplay, but you can take advantage of 3d things too, like nice lighting, etc...

Ok thanks, I hope modeling in Blender isn't as hard as it seemed 4 years ago.

Why don't you head over to the folks at http://openra.res0l.net/?

Their engine is all-round for that kind of game. You can probably use it to make your game.

They even have their own version of dune2k, ra and c&c, for reference.