Submission #6271: DrD2k9's C64 Portal in 03:48.50

Portal - For Commodore 64???

Gameplay Basics

• There are 20 rooms in the game: some comments on specific rooms later.
• Character movement is done using the keyboard, while the portal gun requires both keyboard and joystick inputs.
  • It is possible to play this game using the Commodore 1351 Mouse to control the portal gun in lieu of a joystick.
• Room info:
  • Switches drop companion cubes.
  • Pressure sensitive pads deactivate yellow walls (which can neither be moved or shot through).
  • Green walls can be walked through, but not shot through.
  • Red walls may be shot through, but not walked through.
  • Portals can only be placed on light grey blocks.
  • Turrets fire/kill when Chells feet are at the same Y-position as their own feet.
  • Jumping/falling is the only method of vertical movement.
  • There is no running; all horizontal movement is the same speed, and jumping does not affect horizontal velocity.

Specific Room Notes

• Rooms 1-3: Assumed to be performed as intended by the designer. (Hereafter labeled as 'Normal')
• Room 4: It appears as though the room was designed to have portals be used by going through the pre-positioned orange portal and exiting a blue portal from the ceiling at the upper right portion of the screen. However, it is simply possible to jump over the turret's line of fire and head straight to the exit.
• Room 5: While it's actually possible to simply run straight across the bottom and do a clipping leap through the wall near the exit. The (assumed) intended method for this room is faster.
• Rooms 6-9: Normal
• Room 10: Likely that the first portal shot is performed from a higher location than expected. Jump back up to the right uses a minor corner clip.
• Room 11: Normal
• Room 12: Companion cube likely meant to be dropped through the yellow wall to block turret. This would require backtracking to the pressure pad. Instead the cube is dropped during a jump off the platform edge so that it lands earlier than Chell, effectively blocking the turret.
• Room 13: Another possible situation where the first shot is able to be performed earlier that developers probably expected players to fire.
• Room 14: Normal
• Room 15: Likely the player is expected to use the companion cube to block the turret fire, then return through the portals, up the steps, and out the exit. However, there is just enough room to simply hurdle the turret jumping from the upper level and proceed to the exit.
• Room 16: It's possible that the player is expected to jump over the gap (dropping the cube in air) and land on the left upper platform until the companion cube has landed to block the turret before heading for the exit. This run instead uses the same technique used in Room 12 for this room.
• Rooms 17-20: Normal routing (albeit probably a bit fancier portal work than expected)
  • Special note on room 18: There is a major time wasting bug in this game. It is impossible to both move the character to the right while simultaneously moving the portal targeting reticle to the left. Attempting to do so will cause Chell to also walk left, even if 'D' (the normal key to move right) is being held down. Therefore Room 18 has some delay because these two movements must be performed separately. In all other levels where leftward reticle movement is necessary it is possible to coincide this movement with Chell's own leftward motion preventing this bug from affecting anything else.

Other Notes

• From the start of the game itself, gameplay lasts all of about 2:18. The credit sequence is longer than the actual gameplay!
• While GLaDOS does appear in this game during casual play (taunting/hinting) between rooms; this run is able to skip those screens completely by use of frame perfect input.
• There is also some pretty nice animation/artwork for the C64; specifically on the pre-title and title screens (unfortunately neither are shown long enough to see in this run).

Pre-Title Screen                        Title Screen

Acceptability of this homebrew game

• It's a finished release version of the game.
• It's fairly well polished game (aside from the couple movement bugs and situations were jump distance allows for an easier solution than was likely expected by the developer)
• While quite new, it does already have multiple third party media:
  • https://www.vintageisthenewold.com/tribute-to-portal-in-development-for-the-commodore-64/ - Preview
  • https://www.vintageisthenewold.com/review-portal-c64/ - Review
  • https://www.well-played.com.au/you-can-now-play-portal-on-the-commodore-64/ Article
  • https://www.youtube.com/watch?v=V9A07AFk1lA&t=696s - video review by The 8-Bit Guy

For the curious