Unable to uninstall Sharepoint - invalid state

Appendix Sharepoint 2013 failed to install and is stuck in an odd state. I followed the recommended method for uninstalling an application using powershell commands on a hosted Sharepoint server, but it does not execute properly.

Visual Studio Deployment / Debugging Reports:

Skip the uninstall phase because the SharePoint application is in an invalid state and cannot be uninstalled.

PowerShell Commands

$instances = Get-SPAppInstance -Web http://mysite/sites/collection
$instance = $instances | where {$_.Title -eq 'Application.Title'}
Uninstall-SPAppInstance -Identity $instance

Executing this PS command ...

 The System Account cannot perform this action.

Sharepoint UI, . powershell ( ), . , .