I missed the demo of 2 because I hadn't yet started 1 so chose not to play it not realising the demo only had limited availability. I'm now close to 100% 1 and real enjoyed it. So what have they improved, changed, new features brought in etc.?

I completed the game and almost never used any weapons beside the main machinegun for the spider. ATM it's to hard too find them, then get a good one and then even upgrade it. In this time i already upgraded the main weapon. You should rework the weapons. First make them available in the shop, and then make them more useful and may be necessary....

Is this true? Should I buy the first game instead?

When I connect to a mine, the drill digs it's way in but the torpedo explodes immediately on the entrance of the mine instead of flying into it. So it doesn't do any damage except for maybe the first 1-2 blocks. Edit: It always works on the first mine I enter but at the 2-3 mine it stops working...

it says the Tesla Tower is blocking the way... what can I do?