Crimson Hell -> FREE
I have no idea if this is just a release price, and it'll go up, or if it's just a free game... but I'm enjoying it.
No ads, no IAPs...
Tap to move, auto-fire at the enemy closest to you... upgrades with your level up, get to pick one out of 5 options that change with each time you level up, a'la Solomon's Keep (but with 5 options...)
I'm on stage 2 right now, and haven't run into any problems... hoping I don't get 25% of the way through or something and have a "would you like to keep playing? 99 cents!" message pop up or something... but there's no IAPs listed in iTunes... so... here's hoping! =oD