Thanks to AgentXMan's constructive suggestions, a few adjustments have been made:

1. NPCs' health increased.
2. Adjustment on the overall difficulty,
3. Shield now regenerates health.
4. Added tips after dying in the boss fight (you can actually dash while being trapped).
5. The player can no longer move around while lock-picking.
6. Minor improvements on the lock-picking system.

AgentXMan plays a lot of indie games and give each of them very detailed feedback, feel free to visit his channel!