Time monsters come back during a short period of time. When you kill a time monster and suck up its Time Crystals you will get money. Wait for Time Monsters to come back, then keep killing them. You will gain money every time you do this.

When you have completed the sixth level, you can go back to the Time Factory (or Tom Tom Base). Go to the easiest level and complete all of the missions. After that, you should go to a Boss stage. Complete it. You should then switch teams. So if you are a Tom Tom, you will now be a Time Sweeper. Go to the Pause menu then go back to the team that you were on. Talk to everyone in your Base or Time Factory. At least one of them should want to join your team. From there, they will tell you what to do. Do this until you have all the Team Members.

When you play as the Tom Tom Gang by a Winterfield Sniper Rifle, Carlos will ask you if you are going to the lockers. Answer "Yes" and equip the sniper rifle as your second weapon. When you get out of the lockers, change your weapon so that the sniper rifle is on your back. When you zoom in on his back, you can see in the reflection of his gun a village with tall buildings. If you turn around, none of those things are there.