A fun run with a progressing challenge and variety of scenery and objects to jump over. I didn't make it to the end, but maybe you will - good luck!

A really fun vertical climber with a ton of different strategies to ascend to the top.  I think this one would be good for casual players as well as more advanced gamers.

An interesting shmup in disguise.  Definitely tricky with difficult controls at times, and limited firing radius for you (but full radius for enemies).  It's definitely a fun challenge.