A decent game. There are, however, a few rooms you *must* take damage in (or at least I see no way around it) such as this one particular fire room that shoots alternating horizontal and vertical fires on the steps. Also it's entirely luck as to where you end up and levels are selected at random, including levels you've already completed, so it's entirely possible to "luck out" and get easier levels and do better one run, even getting the same exact easy level a few times, or to get "unlucky" and constantly get, say, that one fire room mentioned.
There have been a slight few times I've taken deaths on the falling platform rooms too, due to the character becoming nonresponsive to jumps, although this only occasionally happens, but it is an instant death when it does.
Much of the medal collection in this game is a combination of skill and getting somewhat "lucky" in the rooms it sends you to as well as somewhat "lucky" in what weapons it gives you. (Uzi is terrible, for example).