LEGO Indiana Jones for Nintendo DS - Red Bricks & Extras
Finding the red brick in each level unlocks various "Extras," such as mini-games and other bonuses. Once you've unlocked an Extra, go to Indy's office at Barnett College to buy it.
After unlocking mini-games head next door to the Game Room to play them. To turn on bonuses like Fast Build, stud multipliers and Invincibility, press Start, select 'Extras', then scroll down the list and press A to toggle each bonus on/off. These need to be activated each time you turn on the game.
TIP: If you're trying for 100% completion, I'd recommend unlocking the stud multiplier extras as soon as you can. These make every stud you find worth 2, 4, 6 or 10 times its usual value. Stud multipliers are cumulative, so if you turn all of them on, you'll get 480 times the loot (2 x 4 x 6 x 10 = 480). At that rate it won't take long to buy all the Characters and Extras.
Here's a complete list of unlockable Extras. The exact location of each red brick appear in the level walkthroughs in red text. 
| Level | Extra/Mini-Game | Cost |
|---|---|---|
| R1 - Lost Temple | Scholar Access Panel Mini-Game | 20,000 |
| R2 - Into the Mountains | Raven Stud Shove Mini-Game | 50,000 |
| R3 - Cairo Street Fight | Military Access Panel Mini-Game | 20,000 |
| R4 - Well of Souls | One Shot Extra | 1,000,000 |
| R5 - Rescue the Ark | Whip Drag Survival Mini-Game | 50,000 |
| R6 - Opening the Ark | Fast Build Extra | 300,000 |
| T1 - Shanghai Showdown | Whip Drag Mini-Game | 50,000 |
| T2 - Rapids | Score x2 Extra | 500,000 |
| T3 - Pankot Palace | Chilled Monkey Brains Mini-Game | 50,000 |
| T4 - Temple of Doom | Thuggee Access Panel Mini-Game | 20,000 |
| T5 - Escape the Mineshaft | Beetle Platter Mini-Game | 50,000 |
| T6 - Battle on the Bridge | Regenerate Hearts Extra | 1,000,000 |
| C1 - Retrieving the Cross | Score x4 Extra | 1,000,000 |
| C2 - Tomb of Sir Richard | BOTCS Access Panel Mini-Game | 20,000 |
| C3 - Rescue Professor Jones | Score x6 Extra | 1,500,000 |
| C4 - Zeppelin | LEGO Logo Survival Mini-Game | 50,000 |
| C5 - Canyon of the Crescent Moon | Score x10 Extra | 3,000,000 |
| C6 - Temple of the Grail | Invincibility Extra | 2,000,000 |