Explodemon

I recommend going for this last because these will be the most difficult for most players. Also, you will want to have a fully upgraded character to make your life easier as you dash towards the finish. You shouldn't be going for any extra items since you should already have an S rating on the levels, full speedchargers, and have already bought the upgrades meaning you don't need to collect credits. Below are the required times for each level:

1-1: 3:00
1-2: 3:05
1-3: 3:05
1-4: 2:10

2-1: 4:20
2-2: 5:40
2-3: 2:25
2-4: 7:10

3-1: 4:01
3-2: 4:00
3-3: 2:15
3-4: 9:00