Simplify the following text for a Grade 8 native English-speaking person.
Original: Halo 3 sales reached $ 170 million within 24 hours , making it the biggest selling entertainment product launch in US history .
Simplified: According to Microsoft , first-day sales of Halo 3 reached $ 170 million in the U.S. , setting a record for highest gross of an entertainment product within 24 hours of its release . The performance beat the previous record setterâ '' Halo 2 â '' which earned $ 125 million within 24 hours after its launch .