In the Temple Run 2 Upgrades menu there are a few things you can do. The first thing you’ll notice is that there are multiple players you can unlock. The the others things available are the Power Up and Ability buttons which will take you to areas that will let you configure your character and are defined below. One thing you should know is that any ability you upgrade will also be increase for all other players.
For more info check out the Temple Run 2 Guide Wiki
Shield – This will be your first available power up and will save you from 1 mistake for a limited time. After the time is up the shield will disappear. When compared to the similar skill Boost which will make you invincible and catapulting you forward a short to long distance very quickly, Shield will offer much less protection, but a better chance to grab those chests and gems.
Coin Bonus – When you reach a certain distance the value of coins will go up letting you to get more faster. Each upgrade in the abilities menu stays though the description changes. Example: 2nd upgrade says values double at 1000m, 3rd upgrade say they triple at 3000m, you now have both the second and third upgrade. You must get this as soon as possible if you think your gonna be in it for the long haul.
Boost – Makes you completely invincible and sends you running at great speed forward. Will help get you to your Coin Bonus faster and more often. Traveling at fast speeds can cause you to miss chests and gems.
Score Bonus – This will increase your score every time you fill your meter or when you find it in a run. Helpful for tying to get the best score in the world…possible.
Coin Magnet – Gives you a magnetic force that will attract every coins you pass no mater where you are. This can be very useful at high speeds when your along ways in and can really only focus on not dying.
Gem Bonus – Not sure yet, just started out. My guess is that it will increase the power of any power ups found while running like adding gems in the top right corner. If so this would go great with the Pickup Spawn ability which increases the frequency of coming across P Ups during a run.
These count across all character so you don’t have to worry about increasing for everybody separate. It’s a good idea to try and Max everything out because power up found randomly while running with the idol will be effected by these stats.
Wheel Bonus – When you spend gems to continue after you have fallen or crashed you will also get to spin a wheel that can reward you with gifts. This is pretty expensive and gems are very hard to come by so this should be one of the last skills to raise
Coin Value – You most valuable skill as it dramatically raises them amount of coins eared in a run. Max ASAP.
Shield Duration – Helps for a little protect out in the field.
Coin Magnet – A big helper when it comes to grabbing coins at high speed. These are also the places with the high coin values. A must for raking in cash fast.
Boost Distance – Good to have max out for the longest distance when used as this is great for getting out of tough spots like mine carts.
Pickup Spawn – Increases the spawn rate for the 4 power ups found randomly during play Shield, Boost, Coin Magnet, and Meter Fill. Can make those objective a little bit easier.
Power Meter – This is a fun one that lets coins fill your meter faster which in turn lets you use your equip skills more often.
Save Me – Will help keep the first couple gems fees for dying be cheaper, but gems prices will go up by very large amount after 5 or so payed continues after crashing. Not very useful because of the rarity of gems so max out last.
Head Start – Shouldn’t be invested in until your running out of thing to spend currency on. Paying to get a head start can be like throwing money away.
Score Multiplier – Will help you get a higher score making objectives and personal goals easier to reach.
Bolt Distance – You must purchase Usain Bolt from the store to unlock this ability. When equip you will initiate Boost and Magnet at the same time letting you maximize your currency gain.