I think I said this before...
The game is, besides the lag, buggy as hell. I could access all the levels without even beating the second chapter. Also, as I said when you released AltSHIFT, there is no humour compared with the previous games (Where is the timer?).
If you can, please, make a final edition of SHIFT with the classic characters, where they finally defeat the prof; the original professor was way more meany than this one. Also, I don't like the style of the cutscenes, mainly because of the lag too...
However, the levels are way more difficult than in any other edition of SHIFT and that gives it a good point. Also, I loved the boss fight, a bit simple but innovating. But the bugs ruin it.
TL;DR: Bring back the classic style of SHIFT and finish the saga with a great game, with timer, jokes, original characters and add the new elements of the puzzles and the boss battle. You will make a masterpiece.