The minimum amounts of time bonus needed for a 1-Up in each 5% cool points bracket is as follows: 100% = guaranteed 1-Up 95-99% = 30 seconds 90-94% = 1 minute 85-89% = 2 minutes 80-84% = 2 minutes 30 seconds 75-79% = 3 minutes 70-74% = 4 minutes 65-69% = 4 minutes 30 seconds 60-64% = 5 minutes 55-59% = 6 minutes 50-54% = 6 minutes 30 seconds 45-49% = 7 minutes 40-44% = 7 minutes 30 seconds 35-39% = 8 minutes 30-34% = 9 minutes

The highest the time limit starts at in any level is 8 minutes, except the first level only gives you 6 minutes. There are only 2 clocks in each level, which each add 30 seconds to the timer, so the only way to get a 30-34% 1-Up is with Game Genie.