Beginning as a domestic PC package game in 2000, Seal was reborn in 2003 as Seal Online, a full 3D cell-shaded online MMORPG that made its mark on the local gaming market. Armed with cell-shaded graphics and its signature humorous gag action, Seal Online attracted roughly 1.1 million players within just two months of release. Since then, the service has expanded to Southeast Asia and Greater China regions including Japan, Taiwan, and Thailand, maintaining steady performance in the global market.

Now, the Seal IP is evolving once again into a new title following Seal M. The most crucial aspect for the developers of Seal M2 is striking a balance between that distinct 'Seal-ness' and a 'modern MMORPG'. Through a different story and systems compared to its predecessors, the title aims to showcase a fresh side of the Seal IP that has spanned over two decades. While inheriting the cell-shaded graphics and gag action of the original work, the game reimagines combat, progression, collection, cooperation, and competitive content tailored to contemporary mobile MMORPG players. Rather than simply inflating the volume of content, the focus was placed on building a robust structure where each system connects organically.

Specifically, the game establishes class-specific specialized combat by organically connecting three core combat styles: switching, combos, and enhanced attacks. Furthermore, it highlights progression systems featuring equipment enhancement, pet growth, and the collection of costumes and OOPARTS; various cooperative and competitive content such as party dungeons, the Tower of Sages, the Battlefield of Challenge, and world bosses; and an item trading ecosystem via the marketplace.

Seal M2 is set in 'Shiltz', based on the original work but with new elements added. It starts in a familiar world, yet unfolds in a way that reveals different aspects the deeper you delve into it. Under the premise that 'familiar paths stretch in reverse', the game intends to show that it is not merely repeating the nostalgia of the Seal IP, but rather continuing a familiar world through a fresh perspective. In particular, veteran players of the previous titles will find familiar landscapes and elements while simultaneously tasting the fun of discovering the subtle, distorted truths of the world as the adventure goes on.

Seal M2 launches with 5 distinct classes. They are designed based on different combat mechanisms such as switching, combos, and enhanced attacks, rather than just differing in their choice of weapons. While supporting auto-play, the game allows the flow of combat to shift depending on the timing of manually selected skills, pursuing both convenience and the joy of manual control.

The Knight is a melee class that alternates between a shield and a sword. Utilizing shield skills, the knight can grant themselves a shield or inflict slows and stuns on enemies. With sword skills, they deal high damage and utilize debuffs that lower enemy defense. Based on high defense, the knight plays the role of a melee 'dealer-tank' who absorbs enemy attacks on the front lines while continuously dealing damage.

The Jester is a mid-range class that utilizes poison and detonation. Through poison skills, the jester continuously stacks debuffs on enemies, and uses detonation skills to deal damage proportional to the poison stacks. This is a mid-range dealer who evades attacks to maintain a safe distance, accumulates poison, and unleashes explosive damage at the decisive moment.

The Archer is a class making its first appearance in Seal M2, unfolding combat centered around ranged skills. Every time a skill is used, a basic attack enhancement gauge fills up, and when the gauge is full, the basic attack is enhanced. Since the enhanced basic attacks unleash high firepower, the core lies in how efficiently you can connect skill usage with enhanced attack timings.

The Mage dominates the battlefield based on powerful area-of-effect attacks. While skill usage requires a certain casting time, a variety of area skills and combo skills allow the mage to deal heavy damage to multiple enemies. In particular, combo skills increase in potency as the stages rise, unleashing explosive firepower at the final 3rd stage.

The Cleric is a supporter who uses ranged attacks and healing hand in hand. Attack skills accumulate the basic attack enhancement gauge, while recovery skills manage the health of the cleric and party members. When using an enhanced basic attack with a full gauge, an effect that heals the entire party alongside the attack is added. Rather than simply playing a rear-line healing role, the cleric aims for an offensive supporter who orchestrates the party's combat flow by toggling between offense and recovery.

In Seal M2, players can grow their character's appearance and stats simultaneously using costumes and OOPARTS. OOPARTS consist of 5 parts—helmet, face, back, tail, and gloves—allowing for diverse combinations according to player preference. Obtaining duplicate identical items grants additional stats through transcendence, and items of the same grade can be synthesized to elevate them to a higher tier.

Set effects are also provided based on the types of costumes and OOPARTS owned, with grades spanning 6 stages from Normal, Rare, Epic, Heroic, Legendary, to Mythic. Additionally, the Gader acts as a mount to increase movement speed and aid field exploration while granting extra stats through passive ownership effects.

Stage-specific risks apply to equipment enhancement. From +5, failure results in a decrease in enhancement levels, and at +8 or higher, failure risks destroying the equipment. Additional options can be secured through equipment appraisal, and desired options can be locked using the lock feature. Weapons and armor can also be crafted using equipment beads obtained from equipment dismantling along with crafting tools acquired through quests and hunting. If a critical success occurs during crafting, tradeable equipment for the marketplace is produced.

Pets come in 5 types: animal, undead, plant, mystic, and elemental types. They can be obtained by hatching pet cubes acquired in special dungeons, and grown through a succession system that passes down abilities using other pets as materials. Pets that reach their maximum level can be further grown through evolution, and unneeded pets can be converted into the evolution material 'Pet's Heart' through the 'release' feature.

As content and progression systems deepen, the complexity felt by users can also increase. To address this, the developers optimized the UI and UX to make it easy to check necessary information and quickly access desired features.

Cooperative and competitive content with other users is also fully equipped. Ranging from party dungeons for up to 4 players, the lineup includes the Pet Vita Dungeon, the Tower of Sages, field bosses, and the Battlefield of Challenge.

In party dungeons, up to 4 players sequentially clear zones and conquer the final boss. Even without directly recruiting party members, you can play alongside other users through matchmaking. The Pet Vita Dungeon allows you to set the difficulty yourself and provides pet cubes as a major reward. The Tower of Sages is a climbing-type content requiring higher combat power as you ascend floors, letting you test your character's progression level by defeating all monsters within a time limit.

The Battlefield of Challenge is a competitive content operated on a seasonal basis and serves as the end content of Seal M2. Bronze, Silver, and Gold leagues take place over a total of 7 days, and the core is how high of a contribution score you can accumulate within a limited time. The role of pets is also crucial in this process, as securing a strategic advantage depends on how well you utilize your raised pets.

Changes have also been brought to field play. There is a day and night cycle within the game, and when night falls, more powerful field bosses appear. Defeating the night field bosses yields more valuable rewards. Because rewards are determined based on contribution, cooperation and competition happen simultaneously.

Guilds can be joined and created starting from level 22, offering various cooperative systems such as weekly guild missions, attendance, and contribution rewards. Guild donations using personal currency and item support and requests among guild members are also possible. Guild member permissions can be differentially set across 4 titles: Duke, Marcus, Baron, and Count.

The marketplace allows players to freely trade various items such as weapons, armor, and materials among themselves. It supports grade-based filters and search functions, and is structured so that players can compare items with their currently equipped gear during the purchasing process.