Beautiful new slots from Yggdrasil are available on Roobet.. Which one is the best?
If you like cheap slots, you can try Baron Samedi, it has good RTP, and you can bet 0.1$ for 25 lines. Dr. Fortuno is also entertaining with various bonuses.
The reason why people do not really focus on smaller games is that popular games are better, that is why they become popular to begin with. I personally do play on few games and not really look at other ones, of course I do test them out time to time but usually go back to same games after a while.
Roobet also does a lot of giveaways but they usually do it in disguise of making you gamble even more, like they do have stuff like "wager here this much and you get a chance to win big" and they do give one or few people a lot of money as well, but usually not for nothing, usually for doing something. If you ask me, I do not believe they have that much gambled but even if they do, they should be giving away a bit for free without anything at all and not expecting anything in return.