Super Time Force Ultra is a throwback to Contra, with more verticality and exploration to its levels. The trick it adds, is the ability to rewind time anytime you want, or on death, and spawn in a teammate to help complete the level.
There are extra characters to unlock by saving them before they die, similar to how you can save your own teammates. You can also get some bonus characters by gathering enough collectibles in the levels. All characters are unique, but I found some to be vastly more powerful or useful than others. The rocket launcher and samurai sword guys were on my solid GOTO list. Rockets for damage, sword to speed clearing.
Each stage gives you a set amount of time to complete it before you die, so you have to be quick. So long as you can get to the boss with about 10-15 seconds to spare, you can win. Picking up time boosts on the ways helps.
I really enjoyed playing this in my spare time, or with a big chunk of plane/airport time. Really good game.