Irrlicht Engine

I am currently making a retro-styled game and I wanted to make the resolution 640x480, But when I do that, The screen becomes blurry (Old games didn't have blurry screens/anti-aliasing), I'd like any feedback on this.

I suppose you set just the resolution and then use full-screen mode in Irrlicht? Or are you using another way?
The problem is - that was kinda the way to do things in the past when Irrlicht was coded. These days it's not really a good idea anymore. Because it changes the native resolution of the screen - which may not even be supported by your monitor well. And I think then you can run into things like the monitor doing the scaling in whatever way.

The better solution is - render to a texture of whatever resolution you'd like to have. Then render it to a quadratic node which has the size of your monitor resoltution. So now the GPU does the scaling. Or you can even write a shader to write some advanced scaling.

Example 27.PostProcessing in Irrlicht svn trunk does use a screenquad example. Or see https://github.com/mzeilfelder/irr-play ... reenQuad.h for another one. Ignore the shader callback stuff in there, you only need that if you want to use it in a shader. Just think of screenquad of the thing which draws a texture of any size fullscreen.