Woo! I just pushed 1.4.0 of subaku to Apple for review. This adds the time trial mode along with a new leaderboard for the mode.
I saw a photo today of a game with its leaderboard filled with a ridiculous high score held by many people. A simple bug could get this and I think it really spoils a game. I have tested time trial over and over again and am pretty confident that this should provide a really enjoyable mode for subaku.
I cannot wait for it to be approved. I hope you will enjoy it!