Yesterday, we invited some of the top iPhone-focused journalists to our office for SEGA Game Day. We had some lunch (Specialty’s… yum) saw some great new games in action, and then had time to play them. You may have seen some of the tweets about the event — well, here’s everything you need to know about what we announced yesterday.

Kingdom Conquest

Never heard of Kingdom Conquest, you say? Well, that’s because it’s a brand new game! Kingdom Conquest is a free-to-play MMO built exclusively for the iPhone & iPod Touch that puts players in the shoes of an adventurer aspiring to become the new king of Magna Gul, the land of monsters. Chaos has spread like wildfire following the disappearance of the former ruler, El Dor, and his empty throne lies open for the taking…

To win their place as the new king, players must strategically ally with – and work against – other players to gradually improve and expand their territory through a combination of resource management and combat. Cooperating with the right players is crucial, as the alliance that controls the most towers in a season is the one that wins the battle.

There are two modes in Kingdom Conquest — simulation mode and action mode. In simulation mode, players strategically gather resources, form alliances with other players, build facilities, expand their territories, and attack other players’ territories. In action mode, players group with up to 3 friends (via Wi-Fi) to explore and conquer dungeons, defeat monsters, and obtain loot in traditional “hack and slash” gameplay. Items and money obtained in action mode can then be used to help build up the players’ territories in simulation mode.

Game Features

• Compete or form alliances with other players from around the world.
• Earn new Items and powerful weapons by defeating beasts in the dungeon-crawling Action Mode, and use these spoils to defeat other players in the strategy-focused Simulation Mode.
• Unlock more than 100 types of collectable monsters like Crimson Gargoyles, Ice Golems, and Dark Steam Knights.
• Synthesize new monsters with skills that can turn the tide in a crucial battle.
• Trade weapons and monsters with other players via the integrated auction house.
• Communicate with alliance members by using the in-game forums.
• Improve chances of success by purchasing resource stones Apple’s micro-payment system. These valuable items can help boost progress in a wide variety of ways: increased resource gathering ability, bigger storage capacity in treasuries, increased life points, etc.

Kingdom Conquest will be released in Fall 2010 for the iPhone and iPod Touch. Action mode supports 1-4 players via Wi-Fi. Simulation mode supports thousands of players worldwide via Wi-Fi, Edge, and 3G.

Chu Chu Rocket

This is a game that so many of our fans have asked for, and judging by all the tweets I saw yesterday, you’re very excited for.

Just like the original fan favorite from the Dreamcast console, the highly acclaimed cat and mouse puzzler will require players to guide the little ChuChus to their rocket ship before the evil cats get to them first in a variety of different play modes sure to challenge new and veteran players alike.

At launch, ChuChu Rocket will offer over 145 different levels to challenge players as they move mice away from harm and into the safety of a rocket. Utilizing tile arrows to navigate their little ChuChus, players will guide the mice through mazes filled with cats, holes in the ground, and other obstacles.

Game Features:

Wild Puzzles – Help the ChuChus escape the evil KapuKapus in 145 puzzles spread between Normal, Hard, Special, and Mania difficulty levels.

1 to 4 Player Multiplayer Battles – Play free-for-all or in team battle as frantic action ensues across 25 intense multiplayer levels as up to 4 players battle it out via Bluetooth or Wi-Fi.

Tons of Game Modes – Beginner and expert ChuChus alike can enjoy cheese-erific game modes including Puzzle, Challenge, and Multiplayer Battle.

Exclusive iPad Feature – If you thought ChuChu multiplayer was insane before, wait until you try it on the iPad featuring 4player on a single iPad.  Push, shove, and flick your way to victory!

Chu Chu Rocket will be released in October 2010 for iPhone and iPad. It supports 1-4 players (multiplayer via Bluetooth or Wi-Fi).

Gunstar Heroes

As Gunstar twin Red or Blue, defeat Colonel Red’s army to keep him from activating the Mystical Gems and destroying planet Gunstar 9…

As protectors of the planet Gunstar 9, the Gunstar Red and Blue twins must defeat Colonel Red and the Emperor before the evildoers can bring robot Golden Silver to life and destroy their beloved galactic home. Guided by Professor White and their sister Yellow, the twins race around in mining carts and space ships blasting at the enemy onslaught through seven chaos-filled stages. This means WAR!

Game Features:

360 Degree Shooting – As you run through the explosive side-scrolling levels, point and fire from any angle, even backwards over your head.

Loads of Enemies – Carrying two to four weapon types, unleash 10 different attacks on enemies and over 25 Boss battles.

Two-Player Action – Take on the unfriendly fire of Colonel Red’s army with a friend (Bluetooth required – available only for 2nd generation or better iPhone & iPod touch and 3.x OS).

Close Quarters Combat – Throwing, sliding and jumping attacks with 14 unique weapons.

Gunstar Heroes will be released Fall 2010 for iPhone, and supports 1-2 players (multiplayer via Bluetooth).

Altered Beast

In this classic game enjoyed by fans for nearly 20 years, play as a centurion summoned from the dead by Zeus, shape shift into various beasts and fight off hordes of demons to rescue Athena.

Transform into a variety of beasts and fight off throngs of demons to rescue his daughter Athena from the evil Neff. The mighty shape-shifting god, Neff, will challenge you in various hideous forms in each Boss level, but you are armed to the teeth with transformative tricks of your own!

Game Features:

Power Up – Collect three Spirit Balls to power up and transform into a new Altered Beast in each round:  Werewolf, Weredragon, Werebear, Weretiger and a Golden Werewolf.

Fight Evil – Battle five bosses and 17 demon types with kicks and punches while in human form, and special Altered Beast attacks once you shape shift.

Two-player Mode – Use Bluetooth Peer-to-Peer Multiplayer to team up with a friend to take Neff down (Bluetooth required – available only for 2nd generation or better iPhone & iPod touch and 3.x OS)

Altered Beast will be available Fall 2010 for iPhone, and supports 1-2 players (multiplayer via Bluetooth).

Sonic the Hedgehog 4 Episode I

Of all the games we saw yesterday, this one surprised me the most. iPhone versions of newer games can sometimes be simplified versions of their console brothers, but this one is not. It looks the same as the XBLA and other versions we’ve been showing. It was also the first game that all of our editors dove into immediately.

Sonic the Hedgehog 4 Episode I picks  up right where Sonic and Knuckles left off. Dr. Eggman’s back, and in an effort to finally rid himself of Sonic, he revisits – and improves – the very best of his creations. For the first time in a Sonic 2-D adventure, experience new online capabilities with leaderboards to compete with your friends for the fastest times!

Game Features:

CLASSIC SONIC STAGES! Race through traditional Sonic Zones rendered in full HD visual quality.

NEW MOVES! All of Sonic’s classic moves are available, including the newer Homing Attack which will add a new level of control and excitement.

SPECIAL STAGES RETURN! A staple of the Genesis-era games, the special stages return allowing fans to collect the chaos emeralds and turn into Super Sonic.

REVAMPED CLASSIC BOSS BATTLES Dr. Eggman returns with new and improved mechas and will go berserk when he accumulates damage.

Sonic the Hedgehog 4 Episode I will be out in Fall 2010 for iPhone, XBLA,  PSN, and WiiWare.