In practice mode, collecting the double-dash gem will cause the ability to persist through all levels, not just levels after 2200. This means you can use it in 100-2100, as well as already have it activated when replaying 2200, even before touching the dash crystal. This will also continue to happen if exit with clear in practice mode.
In practice mode, collecting the double-dash gem will cause the ability to persist through all levels, not just levels after 2200. This means you can use it in 100-2100, as well as already have it activated when replaying 2200, even before touching the dash crystal. This will also continue to happen if exit with clear in practice mode.