M55 Globular Cluster

First time trying to process star cluster. Actually, the Telescope Live astrophotography picture contests was the goal, but I haven´t really read the rules, so I did't upload it.
40 min of exposure with with LRGB filters and CHI-1 telescope.
I've tried to have the glow in the core without blowing the stars too much. Please, comments and critiques are welcome, I need to improve and any advices can be really helpful. Clear skies!