The play style is a lot different than other shooters and adds alot of depth with the bullet absorbing. It makes it hard, but at the same time, not impossible like other side scrolling shooters. The only problem with it I see is, it could use some extra variations in ships or upgradable weapons. The game is also pretty short, but its pretty hard, so unless you are an absolute professional. Most likely it will take you a good number of tries to beat the game.
Its been such a long time since dreamcast got it, where is the sequel? but its so good that I can play it over and over and it still doesn't get old. Definitely get it at this price point.