"Slug's Sister Defense" is an action game featuring Slug, an overprotective brother who appears in "Goonya Monster."

He is absolutely devoted to his sister, Snail, and will do anything to protect her.

Up until now, Slug's little sister, Snail, has fought off countless foes, from Goos and Undead to various Monsters.

But now, these enemies are plotting revenge...

As Snail faces this danger, Slug — a complete siscon — won't let his beloved sister be threatened.

He'll go all out, becoming an unstoppable force to defend her!

◆ Protect Snail in the Center as Long as Possible!

　 Enemies are coming for Snail, aiming to break through her shield.

　 Slug doesn't take damage, so boldly charge at enemies and wipe them out!

　 Weapons will automatically fire as long as they're equipped.

◆ Deploy Your Weapons!

　 As the player levels up, new weapons and gear become available for acquisition and enhancement!

　 You can place these weapons strategically wherever you'd like and collect them as necessary to adapt to different situations!

◆ Meet the Conditions to Evolve Weapons!

　 When you acquire specific gear and max out a weapon's level, you can evolve the weapon upon your next level-up.

　 Evolved weapons are powerful, boasting upgraded visuals and performance!

◆ Beware of Powerful Monsters!

　 There are unique Monsters with special skills, some of which are specifically targeting Slug to interfere. Stay on guard!

◆ Upgrade with Coins, Too!

　 Coins collected during battles can be used to enhance your gear on the Power-Up screen from the title menu.

　 Gear effects persist indefinitely unless reset, allowing for steady power growth.

　 But if you want an extra challenge, you can reset and push your limits...?!