Slot machine gambling feature?

Mostly out of curiousity: Anyone knows which brands of casino software offer a gambling feature any on their slot machines? Obviously, Microgaming does. Also, Lasseter's and Ausvegas do.

But not Playtech and RTG, correct?

I figure that some of the experienced slot players can answer this right away ...

 

The only 2 I know of are: Microgaming and Player Preferred.

Anyone else? I'm sure there are others - but I haven't played EVERY casino software out there

No - RTG doesn't (unless I missed it somehow). I don't recall Playtech having it either, but haven't played them in over a year.

 

You have Wagerworks (one of my preferred software) but only on their last slot Wheel Of Fortune Triple Action Frenzy (which is just brilliant).
You can play it for free at BlueSquare:
You must register/login in order to see the link.
There is also B3W but only with 5 of their slots (they have the same engine, the only difference is the theme and the denomination).
My preference (just because of the theme) goes to Las Vegas Show.
You can play it for free at Casino Solera:
You must register/login in order to see the link.
I also remember that the Jackpot 6,000 slot from Netent has a gamble feature.
You can play it for free at CasinoEuro:
You must register/login in order to see the link.
MicroGaming has also 9 slots with a gamble feature but it's the UK pub slots.
You can play them for free at LadBrokes:
You must register/login in order to see the link.
The 2 new ones are very funny: Pandamonium and Dubya Money.
Just wanted to mention that Player Preferred is the software which runs the HypeGaming website (you have to download).

EDIT:
You also have a lot of Gambling Federation slots with the gambling feature...but I wouldn't play there if I was you