This article explains how a virtual machine is recovered from an incremental backup.
Yes, you can select an incremental backup when performing a virtual machine recovery or an instant recovery. The backup you select is marked with a date and time, so you are actually selecting a data recovery point. When you select a full backup, the recovery is performed using only the data from this particular backup. However, if you select an incremental backup, the recovery is performed using data from the backup, or recovery point, you selected and all previous backups belonging to the same backup group. For more details, see the Recovery chapter in the Unitrends Free Administrator's Guide.