The very first Megaman game is extremely difficult if you play it normally. There are several factors contributing to this. One is it lacks any sort of back-up, so you had to complete it in one sitting. The other and most notable roadblock for most players, even experienced ones, is the Yellow Devil end boss. Without the use of the select/pause damage trick, he is very difficult to defeat. Another major contributing factor to MM1's difficulty is lack of Energy Tanks. MM1 is the only Megaman game that makes the player fight enemies after reaching the Robot Master's lair. The possibility of getting slaughtered before you even reach the boss is very possible, though I never really considered this a problem. The classic Megaman games force you to battle each master robot a second time on the last stage (Dr. Wily stage). MM1 is the only game that spreads these fights across two separate levels (Mega Man must fight Cut Man and Elec Man on Wily Stage 2, and then has to fight Bomb Man, Fire Man, Ice Man, and Guts Man on Wily Stage 4). MM1 is also one of the only two games in the Classic series that does not allow the player to select the order in which to fight the Robot Masters a second time. In Mega Man 2 through 6, after defeating each Robot Master the second time, a large energy pellet appears. In Mega Man, these do not appear, making the last stage considerably difficult.