is metro 2033 worth just over €7?
I found it to be a very enjoyable and immersive experience. It does a good job of making you feel like a lonely scavenger. While the combat is very familiar with most other games, the way it is designed makes you have to act smart and choose your battles wisely...your enemies will rush, flank, and try to flush you out. The game actually has a reason for why people don't die from one bullet (people living in the tunnels manufacture their own crappy bullets...old, well made bullets from before the nuke holocaust are hard to come by and are used as currency...unless you are in a desperate fight and need to use them for your gun.)
While the story is based on a book, the way it flows is a little similar to Deus Ex. You can either sneak through enemy positions, silently take them down (destroying light and energy sources to aid you), or simply shooting places up. The decisions you make over the game will determine the 'good' or the 'bad' (whether they are good or bad is up to you) ending.
I would say it is a good mix of FEAR and DOOM 3.