multiload

A computer program that loads its code and data in a number of separate stages, typically to work around memory constraints.

The finished game will be a multiload, with the first load allowing players to select which aircraft they'd like to fly.

If it is a multiload game, then you will probably only get the main game part, not the levels […] […] sometimes possible to obtain the loader code, and change it to a suitable format that the emulators will use (called LLT multiloads - Load Level Trap) where the emulator looks for a certain 12 byte loader command to be called up.

To load in separate stages.

The best games like Midnight Resistance made use of the 128 memory and did not multiload (unlike other discontinuous RAM sized machines, like the C64/128 or the Beeb, many Spectrum games used the 128 memory if available, so don't go on about how 128k made no difference and all games multiloaded).