I think any of those spinning type attractions would do very well in that space. The building offers a diameter of around 16m, which would allow for many of the variations on that style of ride. For example, a Polyp themed to the Nemesis monster could be a neat addition.
That said, the building would also offer a surprising height clearance once Sub-Terra is cleared out. The central space is around 11m tall, so it could equally be suitable for something with a bit more height to it, like a Move-It 24 or similar. A ride like that could really offer the opportunity to transform a fairly 'standard' ride into a unique guest experience and therefore something more fitting for a theme park.