Excellently fun game. I took a little while to grasp the exact mechanics -- for example, I didn't realise that bullets were limited for ages, because you start off with a lot, and so I didn't know what the point of picking up the Xs that dead enemies leave behind was -- but that didn't take long to work out. Good distribution of reward chests and enemies (and a good variety of reward chests too!), and the footsteps being left behind in areas you've explored is a really nice touch. A minor complaint: the low "dong" noise you get when you pass through an "empty" square in the between-levels bonus pickups screen makes it sound like you've made a mistake in some way. Beyond that (and the enemies looking a bit too basic graphically which is out of place with the rest of the game), I have no complaints at all. Top fun.