Holdover is a puzzle platformer in the style of the old Metroid series, where you are in control of a girl named Marie who had just woken up from a deep slumber inside an abandoned research complex. A holographic image of Marie's father informs her that she was involved in an accident many years ago, and had to be kept inside a medical treatment capsule for some time so that her organs could be regenerated by scientific means. After listening to her father's advice, she sets out to explore the complex and recover her motor skills which were impaired by her long sleep in the life chamber.
The research facility is a labyrinth of corridors, platforms and underwater sections, presumably caused by flooding in the lower levels of the building. Since you can't swim nor jump very high at the start of the game, the time in which you spent underwater will be limited to how long you can hold your breath. This is indicated by the bubble shown at the top left part of the screen, and Marie will drown when this counter reaches zero. Collecting enough blue hearts, and the ability to hold her breath underwater will improve.
Players can save their progress at any time by using the quick save slot, while maps and hints in Japanese can be accessed by clicking on the capture button at the official site. To download the game, just click on the blue button at the upper right part of the web page and a link to the zip file will appear. Take note that Holdover does have some blood and nudity in it.