: Offer multiple playstyles such as Casual (unlimited lives, no knockback), Veteran (limited lives, retro difficulty), and Legend (unlocked after beating the game).

: Develop a system where, if one character falls in combat, the player can navigate the survivor to the fallen sister's location to resuscitate her and continue the fight.

: Implement a seamless character-switching mechanic between sisters Shinobu (long-range submachine gun) and Maya (close-range sword).

To develop features for (often found as "tn-grimguardiansdemonpurge.iso" in certain digital contexts), you should focus on enhancing its core 2D action-platforming mechanics, which revolve around character swapping and "Sister Rescue". Core Gameplay Features

: Design a progression system where defeating bosses yields new sub-weapons (like origami or anti-demon tools) that open new navigational routes, similar to classic Metroidvania titles. System & Utility Features

: Include an unlockable mode for players to challenge all bosses consecutively after completing the main story.