Ive played one very similar to this, but instead of all the clicking to generate resources you had to build resource generator nodes, and you could expand your base much more than this one has in it's set amount of blocks. But about this game it's really easy on early waves up to around 30 you can do without taking damage from a fresh start, the difficulty is kinda all over the place, some early bosses are hard, them you have a easy boss and them one that is hard again even when you dont really change much about your towers. You cant destroy towers after you build, so going for snipers is probably the best after you get 4 machine guns, the thing is that not just on the resources that have a heavy clicking but also on sp that you get from leveling up, this game requires far too much resources for what an upgrade provides, the first and second upgrades in the skill tree are reasonable but after the third and so on the increase is far too much, not to mention that even at 3 speed the game is really slugsh.