V3.1 Update

1. Added backup slots to the Backup Weapon section. Besides weapons, other non-mounted items can also be placed in backup slots.
2. Further improved the tutorial guidance
3. Fixed an issue where drones could be added in the Training Ground
4. Improved auto-pickup so it no longer repeatedly picks up items dropped on the ground
5. Fixed an issue where some achievements could not be completed
6. Fixed the countdown not displaying in some levels
7. Fixed issues related to music playback during boss battles

1. Optimized the main menu loading process, making loading faster and ensuring the game will not freeze even when loading is slow
2. Minor optimization to item refresh in Endless Mode to prevent the shop from being bought out too early
3. Optimized the UI display to show the effects of weapons/equipment on move speed/turn rate in more p

Added character animations for each room

Added a new character costume: Maid Clear Airborne Mode (Challenge) to unlock

Improved the art of some advanced enemies to distinguish them from lower-tier enemies