Hehe, ok first off saving. You should look into the OPEN TO WRITE and OPEN TO READ commands and the WRITE and READ commands too, learn how to make your own files and file formats, it's pretty easy. Just remember that you need to load in the same way as you save, in the same format. Organise everything you need in your save game file, then come up with a file format. Writing strings is about the easiest method to organise, but it also equates to the bulkiest format, so experiment with file commands and come up with a good system for your game.
Now FPS, 30fps is reasonable, like a first person shooter needs to run at a minimum of about 25fps or it becomes too difficult to aim, so 30fps is fine, but it's still a little meagre for folk with monster PC's. The best method of keeping any PC user happy is to use timer based movement, where you say a bullet moves at 50 units a second instead of 1 unit per frame. Quite a challenge to program, but when it works it means you can have unlimited frame rates and your game just gets smoother and smoother on better spec PC's. You should always allow some kind of user specified detail setting, easy to do with particle systems, and you can specify clipping distances etc, so it's no biggie to make a detail options screen, allowing extra sparkle for higher spec PC's.
And lastly units - that's what they are. Pixels are the 2D equivalent of 3D units. I mean I might make a cube that is 100x100x100 - but the size on screen depends on the camera, I mean that box could be a sugar cube, or it could be a Borg vessel in a StarTrek game. I personally like each unit in DB to be about 1cm as a scale, my terrain tends to have 1m x 1m tiles, or 100x100 units. The scale is upto you though, it's all relative to your engine and camera range.
Van-B
The nature of Monkey was irrepressible!.
