I never knew those.
The arts are kind cool.
They are fan comics, right?
Nnnnynyyoooeoes???
When Sonic the Comic came to an end,
Sonic the Comic Online started not long after. Promoting itself as "Officially unofficial", while it's a fan driven project the Three Nigels have contributed work to these comics.
When Archie's Sonic comic was canceled, the fans eventually started
Archie Sonic Online which consist of fan comics continuing both Pre-SGW, Post-SGW and it's own stories.
Meanwhile IDW Publishing has it's own
Sonic comics which are non-fanon and ongoing, but I'm sure you already know about that.