MegaMari is a Japanese PC game that is essentially a cross between Mega Man 2 and Gradius with a few features from other Mega Man games thrown in. I don’t own the game, but from what I read online, it is evidently part of a series.
Thanks to Luna Hikari for first bringing this to my attention.
I haven’t played the game, but I grabbed a few interesting screen shots from the demo sequence off the official website.
Jump and shoot the MariBuster!
Appearing and disappearing blocks over the spikes of doom.
Gradius part one.
Gradius part two.