Mega Party Game$ is a multiplayer-oriented title. It truly becomes a "party game" by implementing the microgames in several "party" modes that up to 4 players can enjoy together. In most modes, the players compete with one another, to see who can last the longest, or who can complete the most microgames. Also, seven new mini-games have been added to have 4 players compete together. While it includes a few new modes, the single player mode is heavily reduced and doesn't feature the unlockable mini-games from the predecessor. Mega Party Game$ and the later release, WarioWare: Snapped! are the only WarioWare games without plots and story-themed stages.
In addition, you have the ability to play all of the microgames at the start, by going to a "library". Single-player mode remains the same as the GBA version.
The game received generally favorable reviews from critics. IGN gave the game a 7.5 out 10 stating it as a "fun multiplayer game that suffers from a bad case of deja joue." GameFAQs gave the game a 7.5 out of 10. Metacritic gave the game a 76 out of 100 based on 46 reviews. Eurogamer Kristan Reed gave the game a 7 out of 10 saying that "You've got to fight! For your right! To paaaaaaaaaaarty!"