Casual games should be happy for every sell,
so the task is to get it to as many customers as possible,
(to get more than just 100 sales)
And this means keeping the game as compatible as possible.

Iam not really a shader fan, as shaders are often misused,
thrying to get an ugly grafic to have some special effect to improve it.

A very FPS eating watershader looks rediculus, if there is an ugly
terrain without any contrast next to it....

For me good grafix has one major component: Speed.
A grafical display is not just the single Frame, but
the quality the frames are aligned (meaning the FPS they run)

Casual/Indy games, should use what their natural strength is:
using a fresh and new type of gameplay.
AAA Titels are doomed to stick much more to working genres,
to assure their sales.