A mob of monsters known as the Plob has kidnapped all hundred residents of Boingburg, capital of Slimenia. Only a slime named Rocket has managed to escape the massive heist, and it's his duty to rescue all his fellow slimes and stop the Plob. Dragon Quest Heroes: Rocket Slime is the second Dragon Quest spinoff to feature the series' trademark slimes (the first of which never saw a North American release), which is a surprisingly solid, albeit potentially short, experience.
Unlike main installments of the Dragon Quest franchise, Rocket Slime is an action game, with Rocket bouncing across various environs. The player can stretch and launch him at enemies to damage them and launch them into the air, during which he can catch them; Rocket can hold up to three enemies and/or items lying around dungeons. He can also toss whatever he's holding at other foes to deal more damage, or throw them onto mine carts to Boingburg. Moreover, he can fully kill enemies to gain money and an occasional item sack that he can too put on a cart to send home. Rocket himself can take damage from enemies, though, with a number of hearts indicating his HP, and the player can occasionally find Seeds of Life to increase his number of hearts. There are also occasionally fights with bosses that require some sort of strategy.
Rocket Slime also features occasional tank battles with members of the Plob in dungeons, where Rocket summons his tank to battle the enemy's. Many items found in dungeons can serve as ammo, and certain rescued slimes and even monsters (if Rocket has sent thirty of a kind to Boingburg) can serve as up to three crewmembers. Rocket's tank has two cannons, one that fires directly at the enemy tank and another that fires ammo in an arc towards the enemy tank, with ammo regularly flowing into his tank. Rocket must manually carry ammo to the cannons and throw them in, after which the ammo fires at various speeds to the enemy tank, whose crew in turn fires its ammo at Rocket's tank. Ammo can collide, in which case the collided ammo falls to the ground and magically finds its way back into its respective owners' tanks. Ammo that successfully reaches an opposing tank deals a certain amount of damage to its HP.
Even if Rocket's tank reaches zero HP, however, it's not the end of the battle, as the enemy must run over to his tank and destroy its core, with Rocket able to kill the invading enemies, in which case they regenerate at their tank after some time. His tank's cannons are still active even at zero HP, giving him the chance to continue firing ammo to down the enemy tank's own HP to zero, in which case he himself must go over to the enemy's tank and destroy its core to win the battle. Winning tank battles is usually necessary to advance the main storyline and rescue slimes. The player can upgrade the tank's maximum HP with money and certain items, some of which the player can acquire through alchemy, accessed some time into the game.
Overall, Rocket Slime's battles are reasonably enjoyable, with the division between tank battles and field battles adding decent diversity. That Rocket Slime, however, is a fairly easy game (it's possible to complete it without dying at all) might alienate players looking for a challenge. The only real flaw in combat is the awkwardness at times of crewmember A.I. during tank battles, with Rocket's allies sometimes getting in the way and making lousy choices, but combat is still a draw to the game.
The interface and controls are also easy to handle, with Rocket Slime being low-maintenance for the most part, and Rocket moving through dungeons as one would expect a slime to. There are also some occasional extras within the town of Boingburg, such as a few mini-games. The only real shortcoming is the inability to scroll through text while saving the game (though ironically, players can scroll through all other dialogue), but otherwise, interaction leaves very little, if any, room for improvement.
Since Rocket Slime is a sequel, it naturally derives some elements from its predecessor, such as mine carts, rescuing slimes, and the slime movement mechanisms, although it does feature elements such as tank battles that set it apart from its predecessor, and the action-oriented gameplay heavily breaks from the turn-based norm of the Dragon Quest franchise. All in all, Rocket Slime feels plentifully fresh.
It's always difficult to judge the merit of a light-hearted, comical story such as Rocket Slime's, although it does have some things going for it, such as a solid localization, with most of the slimes in the game having their own personality, speech pattern, and the like, alongside endless slime puns. The main villain also has a humorous motive revealed at the end of the game. In the end, one cannot expect a game like Rocket Slime to have a deep, riveting plot, so its story offering is certainly more than adequate.
The soundtrack of Rocket Slime is a bit of a departure for series composer Koichi Sugiyama from his norm, featuring a cheery upbeat style that, while certainly fitting the game, is a bit repetitive and could've easily used more diversity. The game also features sound effects from the series' past, which again fits the title's comical milieu, and even some voice clips for many slimes that again aren't out of place. Still, the music, while by no means bad, could've been more varied.
The visuals also feature a cheery style, with Akira Toriyama providing Boingburg's hundred slimy residents plentiful diversity, and tacking on his signature monster designs as well, with all enemies, regardless of form or species, containing platypus tails in sync with the platypus leadership of the Plob. The colors and environments are vibrant, as well, and overall, there isn't much to complain about, aside perhaps from the fact that Rocket can face eight directions while everyone else can only face four.
Finally, breezing straight through Rocket Slime doesn't take more than a little over ten hours, although there are certain means by which to boost playing time, such as collecting a hundred of every monster for Boingburg's museum, uncovering all items, and a few extra tank battles, all of which can possibly increase playing time to somewhere around forty hours.
Overall, Rocket Slime is a surprisingly good offshoot of the Dragon Quest franchise, a reasonable distraction from the dearth of main installments, and of course endless remakes, of the series. Most of its aspects are solid, and even those who are virgins to the franchise just might have a good time. Still, it might not hold off diehard series fans long enough until the next true Dragon Quest game, but it certainly tries.