Always going to signal boost DYA games. They've got fun retro-style pixel games with great soundtracks and a twist on gameplay, but are always overlooked. All their games are .99 for the sale, which is a steal.
Bot Vice
Gallery shooter with weapon power ups and cover. Gives off Mega Man X vibes. Free extra mission mode added 25 more remixed levels on top of the 25 that were already there. Pretty challenging.
Strikey Sisters
Brick breaker with local co-op, a world map, lots of levels and bosses, and ball power ups/spells to fight off aggressive enemies and take out tricky bricks. Never played Firestriker for the SNES but I've seen it compared to that. Recently got a (free) update that added another 60 levels.
Fantastic. At only a dollar a pop, it's hard to turn these down.
If anyone is looking for a great JRPG with the best combat system I've ever seen in a turn-based game, I really recommend Cosmic Star Heroine. It harkens back to the Chrono Trigger days with tons of characters, thoughtful combat, and pixel-y graphics. A real joy to play through and it breaks my heart how little it is talked about.