The roar of thunder is indeed back, but it could have been much louder.
Raiden IV offers a variety of game modes--including the standard Arcade Mode and an XBox 360 Mode. The Arcade mode is shorter in length when compared to Raiden III with only five levels, but interestingly enough, once you clear them, you'll go through the whole thing all over again with tougher enemies, faster bullets and the game's true final boss. The standard weapons, like the Vulcan, Laser and Plasma Shots, have all made the transition. It's really a shame that no new weapons (or variations thereof) have been introduced seeing how this is the fourth game in the franchise, but at the very least, for the Plasma Shot, you are able to choose between two different variations before playing the game--including one that spreads in three directions. Not a significant change to the formula, but it's better than nothing.
To compensate for the short length of the Arcade Mode, the XBox 360 Mode throws in two new stages for a grand total of seven levels. That's roughly the same length as Raiden III, which also had 7 stages. Even though these new levels are nothing to write home or post a blog about, they do extend the lifespan of the Arcade mode considerably. In fact, the majority of Raiden IV's achievements require that you satisfy specific conditions found in the XBox 360 mode, making it somewhat pointless to even bother with the Arcade mode at all. Controls handle fine on the 360 controller--the directional pad is responsive most of the time--but the absence of rumble support is noticeable and disappointing.
You're also able to download some new playable ships for use in the game, like the classic Raiden MK-III from games past, and even the cute little Fairy. But, you'll have to spend Microsoft Points (about a dollar or so) to unlock them. The good news is that although they add some incentive to the game, they aren't a necessity unless you absolutely want to have them. Furthermore, Raiden IV offers the traditional online leaderboards that allow you to prove your skills to the world. And, like Raiden III, you can collect ship data for the Gallery and view individual models anytime you like. As you progress in the game, you'll eventually unlock Boss Rush mode which has you battling bosses in succession.
The graphics hold up well, faithfully ported in their entirety from its original source, and it all looks fantastic in HD. However, the same can't be said for the music---nearly 60% of it is recycled and remixed from Raiden II, and Raiden II's soundtrack is inferior when compared to the excellent compositions of Raiden III. At least, the badass boss music from the first Raiden makes something of a triumphant return--the likes of which we haven't heard in nearly two decades.
I had been eagerly awaiting Raiden IV since its announcement, and while it fulfills many of my expectations, it falls short in others. A disappointingly short Arcade Mode (eclipsed by the XBox 360 Mode) and lackluster music are just two of the main draws that hurt the package, but overall, Raiden IV is a fun shooter that offers something for gamers of most skill levels.