I've already written about Konami's Gradius at some length in its Japanese PC Engine incarnation, but as luck would have it my latest random pick came up with the 1986 version for the Nintendo Entertainment System. So I'm going to give it a very quick look here and get it off of my to-play pile.
The coin-op game actually existed in two different versions -- a stand-alone cabinet on more powerful hardware, and a VS. System presentation of the 8-bit NES version. The NES version uses the standard arcade-style font that was so cool when the NES was new, while the coin-op and later versions used a more stylized sci-fi font. The game is technically simplified but still manages to pull off a credible rendition of the arcade game, and this home edition is probably better known to most gamers than any of the other versions.
What Gradius did better than most 8-bit shooters was its risk-and-reward power-up system -- the player has to decide how to deploy the generic power-ups picked up along the way; waiting produces more powerful weapons, generally, but it's always tempting to use them up by activating a lower-powered option earlier. Of course, there are always the traditional Konami cheat codes, which can provide all the available features and makes the early going quite a bit easier.
The NES sprite hardware wasn't quite up to the arcade or PC Engine versions' power -- this volcano sequence is kind of underwhelming, as sparse flying rocks don't put the player's Vic Viper in too much danger:
The bosses are also downsized a bit -- the first level leaves the background behind to enter a general void of space, and the boss is smaller than it really ought to be:
And the standard Gradius series Moai heads suffer a little bit of color definition loss, along with some slowdown and flicker when the action gets a little too heavy:
I didn't actually get much farther than this on a quick go; it's still challenging with an addictive one-more-time quality, and it's still one of the major NES titles and the first of a long-running classic series of 2-D shooters. But given the availability of more impressive and playable versions on other platforms, the NES version is the most accessible but not the best rendition of Gradius out there.