m_csquare on 25 February 2017
Considering how many post abt metroid begging thing we have in this site, i'm surprised no one has replied to this thread yet.
Sadly, i think it's difficult to expand metroidvania without diving deeper into puzzle genre. Maybe add new weapons that allow you to solve new puzzle instead of just discovering new areas. For me personally, I want the developer to learn one or two things abt physics puzzle from trine 2.
