I really liked it! Very nice job, the game feels very polished, specially for a weekend-jam standard. I think the fast puzzle approach is a nice way to implement the limitation; the difficulty is well balanced. I only struggled a bit with puzzle 17th, although it was not so hard, for me it was more of a challange than the 3 final puzzles. The music also gives a very adequate sense of urgency.
All things considered, very nice job---you can feel that there is a lot of work put into it.