Heyo! Any engine/framework/toolkit/langauge etc is acceptable unless I guess someone wrote a framework or engine for the theme? As far as the submissions have gone though there hasn't been anything like that as I don't think most consider it a theme so most likely you're good!
Even if we do have someone suggest 'Unreal game' as a theme, we have multiple themes chosen which can be done in any combo i.e only do 1 of 3 themes chosen or try all of them if they can work together.
