OK, there's quite a lot wrong with this map and it most certainly should not be released as a full map - at least move it to the WIP section. There's many rookie mistakes made.
First, visable nodraw surfaces above the cube dropper. Also, the faithplate doesn't fling the cube, you need to tick the 'vphysics' box in the trigger_catapult's flags I believe, doesn't make the faithplate sound either.
Emancipation grills look awful. The emitter should be in the wall, and only the end should be visable. And the grill itself have misaligned textures.
The map also looks very bland. Like 2 or 3 textures used in the whole map.
Not really much of a puzzle, turrets are pretty much pointless as you can just portal under them. Easy. And as Djinndrache's video showed, you can just throw the cube round the emancipation grill and skip half the 'puzzle' - and I use the word 'puzzle' loosely as there really isn't much to work out.
And, why did I get taken to the ending credits after the map? That was odd. Anyway, 2/5 from me I'm sorry to say. Please take more time in releasing future maps and consider uploading to the WIP section first, as it's clear you're very new to mapping.