A classic arcade game comes to iOS or android. For the old gamers or those who like shmups. Decent deal.
Also RayForce ($3.99), raycrisis ($6.99), or RayStorm ($5.99) on sale too. Both on google play store and iOS. Good deals on 90s shoot em up games. I recommend RayStorm if one had to pick between the three. Other two are based on sprites.