GOLD STAR MISSIONS
There are 103 missions and all are very simple with some being slightly ambiguously descriptive. With the races, you only have to reach bronze.
You can access and view your progress by clicking the start button and selecting Gold Stars. Here some below that could be puzzling
Barrel Buster
Perform 2 rolls and 1 spin in the air before your vehicle lands
You have to do combo stunts with the Sports Car at the Stunt Park. Choose the ramp in the middle with the building blocks. Avoid the blocks when you attempt your stunt as they break your combo. For this you need to do 2 barrel rolls and a spin. Once you hit the bottom head straight ahead for the picture ramp, as it will teleport you back to the top.
To do a barrel roll : Left Stick + hold X
To do a spin : Left Stick + hold A
To do a flip : Left Stick up or down + hold A
Cow tipper
Some cows need tough love
Shoulder charge (press Y) ten cows
Demolition Expert
Give your townspeople a little KABOOM
Blow twenty people up with TNT barrels.
Engine City
Listen to those buildings purr
You need to find the engine roof prize capsule which is in the Stunt Track. Then customize five buildings with it. The icon in the customize menu looks like a person on top of a little house. Only certain buildings can be used, so the icon may be greyed out. Select the chrome roof from the list.
Grow Your Own Gold
Can you figure out how to make a gold vein?
Once you have the Goo machine, go get green Goo and throw it onto a gold vein to make it bigger.
Knock it Off
A little horseplay with the mission givers
Shoulder charge Hamm, Slinky or Stinky Pete 10 times
Master Re-animator
Your town is dead....literally
Create 10 zombie townspeople with zombie outfits.
Moving Target
Easiest way to get this is to go to the Paratrooper on top of the hill left of where the stagecoach appears for the Save The Stagecoach mission. This mission re-spawns after a bank robbery. Wait until the mission starts, run to the hill as the stagecoach is stationary and easy for the paratrooper to land.
The stagecoach also appears after you purchase from the Toy Store, but it is constantly moving.
Porcupine
Careful with the cactus, it likes to fight back
There are cactuses around with a spring on its base. Shoulder charge these 10 times. Make sure it hits you back.
Western Collector
There are roughly 450+ collectibles (capsules) so there's a LOT. Make sure you SWEEP every area thoroughly, especially when you do the Zurg Spaceport, Enchanted Glen and Haunted House. They are mostly out in the open, but they can be behind cannons, hidden panels or smashable doors.
The best advice I can say is pick up ANYTHING that floats or open anything that remotely might hold a collectible. By the end guaranteed you'll only have about ten or so missing. If you are still missing some, try these below.
Here are the ones you could miss:
Inside Items
There are each three Enchanted chests, Haunted Chess Pieces and Zurg boxes to open for collectibles around the general town area. Use the weapon you received from the related areas to open them.
Haunted House
Near the Haunted House is a tree with a button that shoots an owl. Next to the tree is a patch of dirt. Use the pick to dig up a prize capsule.
As you first enter the house, after the third key is found, a pair of doors opens to a hallway. Jump across the gap and look immediately right. There's a secret panel. Push it forward to open for a capsule.
Stunt Park
The one with the ramp races is full of easily missed capsules. Here are some below.
Do ALL the races here and events. The Big Ramp Challenge has three ramps at the end. Each ramp leads to a different tunnel each with a capsule.
When you first enter the park, head left for the dirt track right of the unicorn statue. Drive forward until you see a blue and yellow ramp on your left. Go left but do not go over the ramps instead navigate around them. If you drive slowly enough you will see two arches on your left. On top of the second arch is a capsule.
On the same track above, head forward until the track completely ends. Do a 180˚ turn (press Y) and head back. You will ride over two hills, then veer a hard left over to a steep climb. See image below
At the top you will see a pair cactuses on your left on darker dirt. You need to drive onto this area and the capsule is at the top. See image below. The arrow points where the capsule will be.
Candy Store
Once you buy the candy store, throw a ball at the X at the front. There are about 20+ that come out. Keep throwing until you get just gold coins. Some times the button sticks, so you have to throw the ball at another building and come back.
Town Hall Capsule
You can see it but how do you get to it? Go to the hat store and press X and it will drop a platform at the front with a hat. Jump onto the hat and it will propel you to the top of the town hall.