Templar Battleforce RPG is on special for the next five days. At $1.49 Aussie ($1US?) I can say it's most definitely worthwhile picking up. Hell, it was worthwhile when I bought it at full price ages ago.
(edit: actually, is it $4.39 Aussie? Still a bargain).
Pretty much a mixture of Xcom/Laser Squad and Wh40k, turn based top-down squad strategy, but with its own lore and background story. You can create your own squads, level them up with different abilities (there's commanders, scouts, engineers, heavy weapon specialists and gunners). There's several large narrative campaigns with mission objectives varying from "kill everything" to "run away" to "take and hold" to "bugger about turning on electrical cables" and much more. Limited "super/buff"powers, unlimited standard actions, overwatch, heat management (Templars are somewhere between Terminators and Mini-mechs in this world), ammo conservation, melee, engy turrets, everything. There's a tonne of stuff to do and ways of trying to play. And they're all good. Also a "nice" game in that you can respec you troops when you want, no costs, no downsides, so you actually get to try out all these different tactics whenever you want. So you won't get bored on ways of playing, or feel like you been trapped into the wrong focus due to one bad choice (it seems overwhelming at first, until you realize that there's not too many "bad" choices, just different ways of doing stuff). You'll feel powerful and weak at the same time, just like an armoured Marine squad o'death should when fighting against swarms of xeno scum.
Think kind of like Space Hulk, but more tactical (they actually have a SH game as well, but this is a definitive upgrade on that). Don't know if $1 will be worth it for hours of fun? They've got a slightly cut-down free version for you to try anyway. The Trese brothers stuff is by and large very good, all with a high level of polish and depth, and this is one of their best. And for a dollar, you really can't go wrong.
(Cory Trese has heaps of other games too, quite a few of them on special right now, but this one is an absolute corker at this price).