Deactivating shadows

Hello, I'm not a developper, I just happen to play some small games made in unity: is there a way to deactivate the shadows in a smart way ? What I mean is, this game for example http://www.arcadiumplayware.com/MissionLuna.html

may lag a lot simply because its maker didn't deactivate shadows, which have next to no use there, and it's like this for many games. But, simply by using an older graphic card that isn't capable of generating them, ironically I could have more fps than with a more recent card.

So, is there a smarter way than this, like some kind of software that virtualy tell unity or windows that the gpu isn't able to generate shadows ? Thanks.