unlike other games in survival it doesn't seem to go faster and faster- none of the obstacles alone are superhard... whats kills are you mostly pogo punks that jumps around... so try to save items for when you need it and use them and learn the patterns. those extra white diamonds really fastens your run. I had 480000 when the section with like 6 pogo punks came and was saved by an item. then It was a matter of time before I i hit 500 k and took the first to door out.
tip: learn to kill scavengers after buying in early levels. it's risky but they have great drops and helps you level up a little earlier, picking that skill you really need.
what is weird to me is that my main income seems to come from the slot machine by taking the gems I won and bet them. coins in levels are really in small amounts. otherwise good, but seems like icy gifts with different theme. fun levels though.