It's been ages since I played Ikari warriors on the NES, but I don't remember having any problem with the games. They weren't great arcade ports, but I didn't think they were shitty either. Then again, I loved Zelda 2 and Fester's Quest was actually fun (even if I didn't beat it). I also liked Heavy Barrel on the NES. How do you rate that one?
As a kid I was a HUGE fan of Ikari. Victory Road in particular, but the first game as well. VR is like a crazy "that might have been a dream I had" version of the first game. Its in space, and there are suits of armor and swords and shit. Awesome as HELL that game is.
The problems with the NES versions of these games are pretty common when talking about NES ports of arcade games in general. The graphics are shit, everything is slow, every sprite on screen is in a perpetual state of either flicker, slowdown, or just only being only half there. That's actually my biggest problem with NES games in general. Aside from the very early games and overhead RPGs everything seems to flicker all the time. It drives me nuts. The more advanced the games got the worse the flicker got. By the time we got to Mighty Final Fight or the Turtles and Battle Toads games...you could pretty much only see half of any on screen character at a time. People just...put up with it, but it drove me crazy. Nothing in the arcade did that. Nothing on my Colecovision did that. WTF?
Like many arcade ports on NES "enhancements" were made. Ikari 1 is now so f*cking long that you'll probably kill yourself before you finish it. You might even die of old age before you finish it because you can't beat it without a cheat code, and even if you have the code you still might not beat it because even the cheat code is limited.
For Victory Road I have to confess that I didn't try quite as hard to finish this one since when I rented it it was obvious that it was just as bad. It has SHOPS in it for f*cks sake. What the hell is the deal with adding shops to NES ports of arcade games? Stryder, Rygar...these games had no shops in the arcade and were much better that way.
Regarding Heavy Barrel: While Victory Road is my favorite "rotating stick Rambo game" I did love Heavy Barrel. I didn't even bother with the NES version. My arcade got rid of it before I could finish it but I had a chance to clear it a couple of weeks ago when I visited Galloping Ghost arcade in the Chicago area.