Less slipping is only one of the tweaks. Here's the full skinny straight from the manual:
Can jump while aiming upward
Continuously shoot arrows at high speed while holding down B (fire button)
Arrows are faster
Arrows have a broader range of effect
Press and hold A (jump button) while jumping, you can slow your fall
Speed while jumping is slowed down
Reaction time is shorter
Some of these sound extreme, but as I mentioned before, they're all very subtle. With the exception of turbo-fire you'd be hard pressed to notice the differences at first.
The game does still offer the original classic controls as an option.
In keeping with the discussion, I wouldn't consider the game a remake - it's pretty much the NES game with 3D effects, improved controls and Japan's original save system - but it's a very nice upgrade regardless.
Yep, I remember reading about this somewhere but haven't tried it - I rarely play fan remakes, ROM hacks, etc. I have lots of respect for these projects but usually admire 'em from afar. Most I've tried are either too difficult or too buggy or both. And I've never been a big fan of emulation on PC.
Would love to see someone hack NES Kid Icarus with the 3D Classics control changes, though. And have it original hardware compatible so I can put it on cart.