Sonic & SEGA All-Stars Racing

Not really difficult or time consuming. In an average game with 8 people, if you keep in a group and hit the items, you'll normally hit between 5/10 people.

I managed to get this on my 7th game, so its one of those ones that will pop up and be like "Oh cool." It pops up mid game, not at the end.

To clairfy, you need to hit 100 enemies with rockets/gloves/bombs/mines/rainbows/stars/giant rockets. I'm not sure if all-star moves count because i'v not encountered one online. Anything you can hit the enemy with that sends them spinning counts. If the enemy counters, or has a shield, it does not count.

To see how far along you are, go into License from the main menu, and then Achievements and scroll until you find it.

Easiest and fastest way to get this is boosting with friend in private race with AI turned off.

Player who goes for hits just sits on power-up respawn and keep hitting friend who park couple of metres in front then theyswitch.

Achievement pops right after 100th hit but YOU NEED TO FINISH RACE to get is saved for statistics and therefore 'get all' achievement

This way achievement takes about 10-15 mins per player.

From the Main Menu go into Multiplayer and then choose "Play With Friends". The online for this game is likely to be a little dead, so your best bet is to boost it with a Friend. Therefore I recommend one of you creates a match.

Once created the host will automatically be requested to choose a character. Pick anyone you want and once you have done that use the guide and invite your friend into the lobby.

Whilst waiting for your friend to arrive, you can change the settings by pressing the button in the game. I recommend the following settings to be applied...

Course - Seaside Hill - Whale Lagoon
Laps - 7
Private Slots - 7
AI Racers - Beginner
Power-Ups - On
Catch-Up - Off

When your friend arrives, press to begin the race. Now you both need to decide who is going for the achievement. Once decided the method is to either let the person going for the achievement race around the track and use Power-Up's on the opponents around the track, or the other method would be for both of you to drive up to a set of power-ups, then let the person going for the achievement grab whatever power-ups they get and launch them onto the other player that is not going for the achievement.
If you choose this method, by placing the Laps at 7, it gives you and your partner enough time to work on this in a few races since the opponents will drive slow and will take awhile to complete 7 Laps.

This achievement will take a short while for you both to get, but once one of you gets it, swap over roles immediately. The achievement will unlock as soon as you have used your 100th Item in XBox Live races.

Good Luck.