This is my first run, so I'll improve it very soon.

IGT is 32:22 (All levels times from game menu added together), but I think RTA works best for this game. This allows, for example, a speedrun with "Level A" ending in 13.2s to be different from the same "Level A" finishing at 13.3s, small but 20 seconds difference in the worst case (All levels).

My RTA Timing method is shown on the description of the video.

Correct RTA is 00:35:06,505