Here's a bit of an odd one from the history of coin-op games...
First off, this isn't truly a sequel to Vanguard. I'm assuming SNK wanted to hopefully bring in some money by using the Vanguard name again; if this wasn't the reason, then I don't know why this was named Vanguard 2 (and it didn't work since the game flopped, or at least it did here in the States that I know of).
The original Vanguard was a bit of a different shooter, as the perspective would change from scrolling sideways to vertically to even seemingly diagonal! There's not many games out there either where the controls consisted of a joystick and four firing buttons, and some of the game was a bit strange too, like docking with those giant space snakes or worms near the end (ok, whatever! That really made sense!). The game was fairly popular and was ported to the Atari 2600 and 7800 systems.
In this version of "Vanguard" (note the sarcastic quotes), the four way firing scheme is shrunk down to one, as you're limited to shooting in whatever direction you're facing (rather than firing independently to your heart's content), but you can also drop bombs on ground targets too, a la Xevious. (Actually this would seem closer to being a Xevious sequel, especially since I found one enemy ship looking suspiciously like one from that game, which I guess is why some of the attacks can be a bit vicious, since they're not happy with having to work another job by being in two games.) The scrolling is different too, as you can now control where to go, and there are no energy pods that will make you invincible briefly like in the original (which would help with this game's difficulty level).
And the gameplay is totally different too: you fly above some sort of moon bases and it's your job to bomb a certain amount of pods before going after the main core. Sound familiar at all, [original] Vanguard fans? Of course not! Again, this is Vanguard in name only.
And that's pretty much it; hunting around for pods to destroy before going for the main target can be a bit time-consuming, plus you've got enemy ships attacking as well to contend with (along with the occasional ground target firing as well, but that's to be expected here in Xevious 2--err, Vanguard 2, I mean). At least the graphics are pretty good, and this was one of the earlier parallax-scrolling games I had ever seen. If you were to ever find and play a game of this today, I could only imagine how surreal it would be in that cockpit (I don't know if a standup version was released, as I only saw this at one game room ever back in the day), since it doesn't have a lot of sounds (and it's few sounds are a bit annoying); playing it in a noisy game room, I didn't really notice how quiet it was with no music until I played it on MAME years later.
The game's also a bit difficult (just try making it to the third level as it is), which I would give this a 7, but I feel the difficulty level is a bit too high for that, although it's not a bad game, it's just not Vanguard in the least, and not as fun. And not giving players an extra ship until 30,000 doesn't help matters any either.
And on a side note, you actually can destroy the core without going after the pods first, but the firepower guarding it is pretty strong though, so that's not exactly the best of ideas.
But then, calling it "Vanguard 2"...yeah, real good idea there too. (confused) 6/10