Hi there. Just wanted to reply as a somewhat old member of the community and a fairly well versed scripter.
This script you're asking as a fairly involved script and extremely difficult to complete. Ruby does not natively support 3d and what you're pretty much asking for is a script that allows sprites and enviroments to be rendered in 3d. This is possible using outside extensions, specifically DLLs created to complete this but it will still take a good amount of time. (Of course if another scripter knows a good way to do this feel free to correct me.) Being that it will take such a large amount of work it is highly unlikely that someone would do this for free, especially for someone that just recently turned up in the community.
Regardless of that, this is actually not quite enough to go on to create the script to begin with. Do you want this to be activated at all times? Do you want the "tilt" to be tunable? Do you want to be able to disable this and activate it. Are there any special types of scripts this would need to work with? Since this would affect maps, it would be nice to know if you plan to do parallax mapping or are just using normal mapping.
Finally, all-in-all I don't think this script would do what you think it will do. Adding a 3d perspective by your game does not add anything to the gameplay and actually will probably look bad unless the rest of the environments are rendered in a clever way. I personally think you'd be better off sticking to just a standard 2d viewpoint.
All this being said, I THINK a mode 7 script and DLL exists on an external website, I just don't remember where.