Frantically reducing file size of a Unity game in the middle of the night

We were originally developing this game for Create Jam Spring 2024, and just about ready to wrap up and go to bed. This was kind of a big deal, because both of us had planes to catch the next day, and so our deadline was that night. Well, we had the game in that janky but playable state one wants and expects for a game-jam, and started building.

Unfortunately, the final build size clocked in at 2,4Gb after zipping – way over the Itch.io file size limit of 1Gb. One forum post said that the Itch.io command-line tool Butler might let us upload 2Gb, but neither of us were in the mood to manage authentication of a command-line interface. Besides, 1Gb file size seems like a perfectly generous limit for a game-jam-game. So something had to be done.

There we were, googling how to reduce the footprint of a unity game, and what we ended up doing was a combination of

• Maxing out compression of image files
• Enabling a high degree of 3D model compression (accepting the risk of weird polygonized models)
• Deleting the landscape assets outside the expected play area. This had two benefits:
  • Some of the landscape assets was now completely unused and thus not included in the final build.
  • The navmesh became much simpler and thus took up less space (it looked pretty complicated before)

After some post-jam tweaks (see next posts) I have taken this further by tuning the navmesh parameters. The navmesh is now a mostly flat plane except for the places which the player can actually be expected to visit.