Rare Replay
200 Achievements
4,000
200-300h
Battlemaniacs
Battletoads: Knock down 500 enemies over time.
15
0.85%
How to unlock the Battlemaniacs achievement in Rare Replay - Definitive Guide
Turn on infinite lives.
I also recommend to keep killing them after getting the achievement to get 999999 points for the 1,000,000 points Achievement, after reaching 999999, just a start a new game in another save and play the game until it pops, for me, it popped on Stage 2: Wookie Hole.
This achievement requires you to defeat 500 enemies, as a cumulative total across all playthroughs of the game. You'll work a long way towards this in the course of a standard full playthrough of the game, but will likely not reach the full 500.
To complete the rest of the required cumulative total, my recommended approach is to start a new game and make a manual save immediately as you begin the first stage. Now play through the game as usual, accruing enemy knock-downs and points as you go, and taking advantage of each opportunity to eat flies. Once you reach a point where you start to have difficulty, just reload your manual save and repeat as necessary. This method readily combines with the "Gargantuan Score" achievement.
Note that you can't use the 'rewind' feature to work towards this.