Open up all levels at the beginning of the game, or choose for a linear progression model instead?
I was thinking maybe I will give the player the choice to pick from all the levels, except the endboss. Once all levels are completed, they would get to the final level.
Even though the story is linear, it is not primary to the game. You could still choose to do the levels as intended. Alternatively, I could open up two levels at a time, so if a player cannot finish one level they could still progress.
What would you do?