Presenting a set of difficulty settings for players to choose from at the beginning of the game is one of the most common practices for tackling the initial skill gap. If possible, you should allow for this setting to be changed on-the-fly from within the options screen. This ensures that players are not entirely constrained by their initial choice, should they find themselves mismatched to the gameplay challenges at hand.
Difficulty settings may seem like a trivial system at first, but determining what to change and how to change it without sacrificing playability is the hard part (pun intended). The most common and often the easiest approach is to create multipliers for basic game parameters such as time or move ...