Defeating a tank gives Rocket a specific item and sometimes a Slime, who returns to Boingburg.

After a certain point in the game, the rescued Slimes rebuild Boingburg and return it to its state in the prologue.

Early on, the player only has the ability to save their game, but eventually gains access to much more, including tank customization, a shop, a tank arena, a surfing mini-game, and an area where the player may synthesize items using recipes that are collected throughout the game.

While in their tank, the player may use the Elasto Blast attack to break their computers, making it more difficult for them to retaliate.

Dragon Quest Heroes: Rocket Slime is based in the fictional world of Slimenia, specifically in the capital city of Boingburg.

It begins with four Slimes, Rocket, Hooly, Bo, and Swotsy, who are playing in front of the castle.

Afterward, an organization of platypus-like creatures known as the Plob invades Boingburg, capturing 100 of its 101 inhabitants.

[4] Because he was distorted and long, the Plob mistakenly believed Rocket was not a Slime but a worm, and discarded him into Forewood Forest.

There, Rocket begins his journey to rescue his fellow slimes, who have been locked up in large treasure chests.

[4] The developers did not want to give the protagonist a sword and shield, feeling it would make the slime character into a blue Link from The Legend of Zelda.

[4] They also rejected having the character breathe fire or run fast like Sonic the Hedgehog, so they refocused on what a slime could do, and that his how they discovered that his movements should be stretching and catapulting itself like a slingshot.

[5][6] Early in the title's life, the developers had a version of it that uses the touch screen to use Rocket's Elasto Blast technique, but scrapped the idea, due to it being too hard to control.

[6] To build on the slingshot paradigm in the second game in the series, the design team added tanks.

[4] The developers also chose to keep humans out of the game, due to that if they did appear, they would probably just run around killing all the Slimes.

[4] The success of Dragon Quest VIII in the west prompted an international release for the Slime series.

[7] Watabe said that if Dragon Quest Heroes sold well, that the developer would look into a sequel, and they may also include Nintendo Wi-Fi Connection support.

[6] Rocket Slime was developed originally for gamers who were eight to ten years old, but in the west the average purchaser's age was twenty five.

[9] Nintendo Power praised its multi-player tank battle mode, calling the game a "well-placed and satisfying adventure".

[9] Play Magazine commented that Rocket Slime is a quality spin-off, adding that other developers should take a cue from it.

[9] Edge noted that while it wasn't a bold game, it had little to criticize, calling its developers "masters of their craft".