"When they say "classic," they really mean it. 3D graphics generally look awful on the DS anyway, but I know Nintendo's system is capable of better than this. There's a reason why people stopped making games that look like C.O.R.E as soon as they could. It's because games that look like C.O.R.E look terrible.
There is no reason to play this game, unless you absolutely hate your hands and want to know what it would be like to have absolutely no fun whatsoever. I appreciate the sentiment of wanting to bring an old school shooter to handheld gaming, but it simply shouldn't have been done. At the very least, it should have been done with at least a vague optimization for the DS' strengths and limitations.
Please don't play this game. You'll have a bad time."