When you’re opening your project, is the first map loaded a big map with a lot of stuff in (props, fx, light, actors)? If yes, that’s probably why it takes this long.
To change that, go into Edit → Project Setting → Map & Modes. Under Default Maps, you have two options:
- The Editor Startup Map is the map that will be open when you’re opening your project. The bigger the map, the longer it is to open your project!
- The Game Default Map is the map inside of which your game should start (as your Title Menu map, for example).
Just change your Editor Startup Map to a lighter map. You can create a new map with nothing in it and put it as your Editor Startup Map for a quicker engine opening :).