Optimize Shadows for Moving Light

Hi all,

My game is a 2d platformer and I have a player character who moves along with a point light. I've turned on hard shadows for the light and tried something with the Lighting Window (Window->Lighting) and even marked all the static platforms as Lightmap Static in the inspector. However, when I build and run the game and play at full resolution and fantastic graphics, the shadows cause the game to run with lag.

The shadows are a critical part of the game and they cannot be omitted, so please if anyone could tell me how to optimize the game for casting shadows, i.e. predetermine the shadows during build time so that minimum computing is done during gameplay, with a moving light, that would be great.

Thanks in advance :D

Also, My PC Specs: i7 Processor (2.4 GHz), 4GB Video Memory (Nvidia 920M), 16GB RAM, 2TB HDD so yeah I don't think my game currently could be aimed at lower hardware.