Shoot Shoot Nitori: The Golden (specifically "The Golden" which is a sequel)
A goofy and not hard flying shooter where you collect weapons from defeated enemies, and stack them on yourself Katamari style.
I mean it when I say "not hard flying shooter", even with this being a Touhou fangame *and* a flying shooter.
It's made by the makers of MegaMari, New Super Marisa Land and the official Touhou fighters.
So, consistently unique in gimmicks and ideas as you progress, and very player considerate. Getting hit usually isn't enough to make you lose a life (your items just scatter). You can still lose lives if you get really clumsy though (like NSML...or any game). You have multiple lives per stage.
Suggesting it for it's over the top nature (Launch that Katamari of weapons!), and lax difficulty for a flying shooter. It's got a selection of difficulties. It's really short (8 stages) though, and one run has to be done in one sitting. Stages can be done in any order, except the first and last. Losing your lives just boots you back to the character/items/stage selection screens. Lots of unlockables, and easter eggs if you interact with enemies in certain ways.
...The original "Shoot Shoot Nitori" is a fine suggestion too.