Boom Space vs Oinky Tonk
Boom Space
Boom Space is a Spin-the-Wheel game that is similar to games like Pirate Kings or more accurately, Piggy Boom. The game features adorable graphics that help it stand out from among the other games within the same genre, and not to mention, unlike other games that will have you building up islands, this game lets you build planets instead. However, the gameplay is still pretty much the same as what you'd expect from such a game - you'll essentially be spinning a wheel in hopes of getting an action - to attack a player's planet or to shield your own - or a freebie, be it free spins or coins.Like Shark Boom and Piggy Boom, you can collect pets in this game but unlike the latter, your pets can't defend your island. They are simply there for show.
So, in many ways, I'd say Boom Space is more like Shark Boom in terms of its graphics and features than Piggy Boom, Greedy Gods or Pirate Kings. However, the gameplay for all these games are basically the same, so if you enjoy playing one of these games, you'll enjoy playing the others.
Oinky Tonk
Oinky Tonk is a casual game where you get to spin a wheel to decide whether you can attack another player, build your island, or plunder others' islands for money to fund the construction/decoration efforts for your island. There are, naturally, many islands that you will be able to progress to and eventually own.However, you can, in turn, be attacked (destroying some of the stuff you've built) and plundered (lose your cache of cash) as well so it would be wise to have shields on at all times. You can perform retaliatory attacks, thankfully, but this only works if your enemy doesn't have a shield on, obviously.
Generally, this game's gameplay is pretty similar to Pirate Kings and many other casual "Spin the Wheel"-type games, including its adorable graphics and fancy animation effects, and hence, Oinky Tonk would serve as a great alternative game to play.