arcade glitch - Tower 13 - Adventures In Body Saving

[Submeg]

If you complete the second level without having lost a life in either the 1st or 2nd levels, the time bonus continues past zero and never stops...

[Harrison]

Sounds like a bug in the actual game code. Not much we can do about this. If you want to try and fix this maybe try contacting the game's developer if it is listed in the game.