There are 6 stages in Battletoads arcade. There are no limits to lies or continues so skill doesn't make a difference, just keep mashing those buttons! :)
Stage 1: Protect the Starship! which begins in space on one of the Dark Queen's space battleships, with many others firing in the distance. Being the beginning of the game, this stage is a simple, straightforward fight against the various rat and pig enemies. The boss at the end is General Slaughter, who can kick the 'Toads off the screen and out of a life, though the 'Toads can do the same to him.
Stage 2: Ice Cave is set in an icy cavern with new rat enemies and environment hazards. The boss of this stage is Karnath the Serpent (presumably the ruler of the snakes from the Snake Pit stages of previous games), who lurks in the deepest areas of the cavern and makes attempts to eat the 'Toads; upon his defeat, Karnath is violently decapitated.
Stage 3: The Dark Queen's Battleship is set on the Queen's main space battleship where more new types of rats appear, including the clones of General Vermin, and the 'Toads will have to watch out for the jet burners and incoming enemy aircraft. The boss of the stage is not the Queen herself (whose holographic presence in it is merely for fan service purpose), but rather Scuzz in the Robo-Rat mechanical armor. After defeating the Robo-Rat, a bonus stage begins in which the 'Toads must destroy its spacecraft as fast as possible, similar to the bonus stage in Street Fighter II.
Stage 4: The Cave Pit is a downfall level similar in concept to the "Wookie Hole" stage of the original Battletoads game and other similar stages. Using jetpacks, the 'Toads must descend into the pit and fight off incoming enemies. During this stage, the player can unleash a screen-clearing Super Smash Attack. This level has no boss.
Stage 5: The Dark Queen's Mansion takes the 'Toads down a long hallway in which nearly every type of enemy from earlier in the game appears and must be defeated. At the end awaits Big Blag, who attacks with powerful stomps and can increase his size to flatten the 'Toads.
Stage 6: The Final Confrontation is the final level of the game and its gameplay is completely different from any previous part of the game, for it adapts the gameplay of a shooter rather than a beat 'em up and the 'Toads must shoot enemies from on top a spacecraft; in addition to the return of the Super Smash Attack, the 'Toads can collect other power-ups to utilize different weapons, such as a flamethrower. The stage takes the 'Toads across the sky and through an enemy fortress before reaching the final boss, Robo-Manus. When Robo-Manus dies, he shoots down the 'Toads spacecraft in a final blow, sending the trio crashing onto a nearby planet. Fortunately, they survive unharmed (being the heroes of the game), and quickly return to the Vulture thanks to their teleporters which they just happened to bring along.