I did not realize the practicality of the rewind feature included in Mega Man Legacy Collection until at least half way through this game. Say you are avoiding five sequential enemy shots. With a save state, you can save at the beginning and return to the beginning, and perhaps make an incremental save after clearing the first shot. The problem is, you have to enter a menu to do this, which is overly complicated. With the all new rewind feature, you backtrack over the moment where you mess up, and move forward where you don’t, in game time. No menu involved.
You could easily make an analogy between Commander Keen and the first Mega Man. The level design and power-ups were unique. Unfortunately, the game is an exercise in frustration due to the difficulty level. I understand some people enjoy a challenge, but I find overly difficult games masochistic. What’s interesting is the sequel, Mega Man 2, gets the difficulty just about perfect, where you aren’t frustrated at any singular moment. While Mega Man laid the groundwork, Mega Man 2 simplified the challenge and made the levels thematic.