you don't need to do the 5 peg or higher puzzles! you can beat the game and do everything with just 4 pegs. and the ranking mode is also optional.
i agree, the harder puzzles and the ranking mode are stressful! when i play, i usually just play 3 and 4 peg puzzles and relax. sometimes i do the 5 peg puzzles but they can take me 5-10 minutes and sometimes i just want to relax!