Sewer Escape

Half-Life 2 Hammer

Gameplay Video

Project Summary

Description: Sewer Escape is a single player level created based on the Original Half-Life 2 to release in 90 hours. This level happened close to Chapter 10 of the Original Half-Life 2. The players need to clean up the Combine enemies in the water tower area and use the car to escape from the area and get back to City 17.  In the level the players will meet the puzzles that they need interact with water and electricity. The players need to figure out when to use the water to cut off the electricity and when to lower the water level to get the electricity back. Also, the players need to use floatable objects to cross the electrified water. Moreover, there will be Metro police in the area that the players need to clean up, and the players will need to face the helicopter at the beginning of the game and at the end of the game.  The player must clean up the Metro police in the water tower area and escape safely.

Editor: Half-Life 2 Hammer

Development Time: 1 Month

Mode: Single Player

Time to Complete: 5-10 minutes

Design Goals

Creating new mechanics by integrating the existing mechanics of Half-Life 2

Creating diverse combat experience in the level

Creating good pacing from Introducing new mechanics to challenging the players with the mechanics

Creating new mechanics by integrating the existing mechanics of Half-Life 2

  • Designed a mechanic allowing players to use water to cut off electricity.

  • Wanted to make water serve more purposes than just functioning as an elevator.

  • Found the mechanic interesting and realistic from a physics perspective.

  • Significant time spent ensuring the mechanic worked reliably without game-breaking bugs.

  • Challenge: battery slot trigger misfired when no battery was inside, causing door script errors.

  • Solution: used logic_branch (Boolean variable) and logic_branch_listener (if-statement) in Hammer.

Creating diverse combat experience

  • Designing diverse combat with only 2–3 enemy types proved more challenging than expected.

  • Final enemy choices: helicopters and Metropolice.

  • Helicopters add verticality to combat and enable use of RPGs, creating exciting gameplay moments.

  • Different combat areas with helicopters provide varied experiences:

    • First encounter: players fight from inside a house, using walls for cover and learning helicopter combat in a safe space.

    • Final encounter: players battle the helicopter in an open area with limited cover, increasing difficulty and intensity.

Creating good pacing from Introducing new mechanics to challenging the players with the mechanics

  • Designing good pacing was challenging due to many mechanics needing to be taught.

  • Final pacing structure:

    • First teaches basic mechanics:

      • Using valves to control water levels.

      • Using batteries to power doors.

    • Then teaches advanced mechanic:

      • Using water to cut off electricity, combining previous mechanics.

      • Tutorial room demonstrates mechanic with visual cues (sparks, yellow light).

    • Final puzzle requires applying all learned mechanics.

  • Enemy spawns placed near target positions to guide players’ attention and movement.

  • High-water tower used as a visible landmark to help players orient themselves and track progress.

Postmortem

What Went Well?

  • Having enough execution to work on the new mechanics that the original HL2 game did not have, which is using water to cut off the electricity.

  • I updated the level effectively based on the feedback.

  • The players did not need to use any cheat mode to finish the combat, and the combat has various verticality that the players need to face in the level. Also, I think the enemies spawn position and the place they came out can also lead the players to the target position, which can be another way of conveyance.

What Went Wrong?

  • Did not think about the conveyance to teach the players about these mechanics enough.

  • The level is not realistic and reasonable enough for players to have an immersive experience through the level.

  • Did not have a clear idea about the time consuming for each task I plan to work on in each Sprint and did not allow enough time for unexpected situations.

What I Learned?

  • It is important to think about conveyance and the gameplay mechanics together while developing the mechanics

  • It is important to create a clear list of the environment and atmosphere I wanted for each area and make sure each area has consistency but also has different meaning and context to the players.

  • It is important to estimate the time consuming for each task more carefully and leave more time to face unexpected situations