Pre-Theme Announcement: Ideas & Restrictions

So, here are my pre-theme, self-imposed restrictions;

• I'll be using Unreal engine 4 (Just because that's the engine I'm most familiar with)
• I'll using (were I can) Blender 2.8 for all my asset creation
• And I'd like to create a "couch co-op" game that I can play with my housemates

Obviously, the theme is king in Game Jams but since I'm creating some art assets ahead of time, I need an established style. 
I think I'm going to go for a fantasy-ish style like Zelda. Maybe GBA Four Swords era type stuff? 
A fixed camera would also be a good idea since it fits well with a one screen co-op game and it means I can "cut corners" on some of the 3D models as I know they're only going to be viewed from one side.