At the start of the game there will be a tutorial on how to use your weapons. Once you are finished with the tutorial, you will be given some enemies to fight. Try to get a high combo while fighting these enemies to get extra DP. Once you have killed all the enemies, wait until you see a circle in the bottom left corner of the screen, indicating the game is saving. Once the circle disappears, pause game play and select the "Restart Chapter" option. Then, fight the enemies in the tutorial again to get more DP. Repeat this process five times to get approximately 200,000 DP. Note: Make sure the first upgrade you buy is "Greedy Perks" so you get more DP from killing enemies. Then, go down the sewer pipe, and stealth kill the indicated enemy. Next, collect all the DP tokens in the area, then buy a cheap upgrade. When you buy an upgrade, it will automatically save the game. Then, pause game play and select the "Restart From Last Checkpoint" option. Collect all the DP tokens again, buy another upgrade that costs 50,000 DP or less, and restart the last checkpoint again. Repeat this process until the upgrades costs 75,000 DP or more. Then, pause game play, select the "Restart Chapter" option, and get more DP using the first method by fighting enemies. Once you have enough DP again, proceed, and collect more DP tokens. Repeat this process until you have all upgrades and weapons to start the game.