I wonder why the default position of charging for entertainment based attractions (excluding CBeebies).
When you think what is spent on the purchase, running and staffing of rides, can you avoid upcharges, and fund it from the ticket price, like with Sea-life.
I think the introduction of a Dungeons would appeal to a wide audience, similar to a new (smaller) ride, and help attract the the GP, so more people through the gates.
Depending on the pricing, and any inclusion/discount of MAP holders, I could see limited opening dates/times to adjust for demand.
Maybe they should try opening House of Monsters during the Summer Holidays as a mini-experiment. Although that said, I do think that Alton should be offering something like this year round, included in admission. It's what makes trips to other theme parks so enjoyable, where there is much more money for entertainment.
I find it interesting comparing this to Thorpe, where for example the scaremazes, I'm a Celeb, DBGT (pre-changes) are all included (with fastrack option)