I just beat the 8 bosses last night, and tried Wily's castle once - got served by the boss

I'll probably try again tonight and see if I can get further.
So far:
-The difficulty is perfect, to me (regardless of where it is in relation to the other Mega Man games).
-As with all the retro MMs, the music rocks. Except the menu music, which might've been good if it weren't a very repetitive 2-second-long high-pitched loop
-It
SUCKS that there is no way (that I know of) to restart a stage or return to the level select without getting game over or hitting reset. And for that matter: what's the point of taking off an extra life and not refilling the player's energy if they don't reach a checkpoint? I know that's how the old games did it but it was annoying then too, and it just seems like some sort of bastard-child feature from games ported over from arcade versions, when they had to punish you for every screw-up so you'd spend more quarters. If I die 2 seconds into a level I don't want to have to reset the game to get another fair try at the stage. This makes dieing before a checkpoint incredibly frustrating because you essentially accomplished nothing and have less of a chance of actually beating the stage without resetting. It's made just that much more annoying because the first stage of Wily's castle is impossible to beat if you get partway, use all you energy for a certain gun, then die and have to restart.