I have problems with playing Gradius NES and Gradius II NES... the graphics disappears all the time. The Vic Viper (Player 1 or 2) has for the most of the time a part visible... same for other sprites.
I've tried it on the FC emulator for Wii, no graphical errors... so the graphic reading for those two games doesn't go well
But sound and other stuff are perfect
game lags too... but that's normal