Exactly what it says in the question, I have an idea for a game but the grid-based aspect doesn't quite fit.
Am I able to skip this design aspect or is it necessary?
Grid-based movement is NOT required. You can make any game that uses elements of the roguelike formula. When you submit, you will be asked if the game is real time or not, just to make it easier for players to find their preferred.
As long as your entry contains elements of procedural content generation that impact gameplay in a substantial way, you will be fine.