ok so u must have cheat engine.
first enter galaxy life
next open cheat engine and change it to double
check your current exp and type it in
u will get 3 results select all of them now use ctrl to select all of them at once and change value of the first number to 99 and then u will lv up and get the resource rewards nut when u reload u will not have your lvl but will still keep
the gold and other resources u got from that lvl up.
oh yea after changing exp u just click on a house or mine to get a little exp then u lvl up to get the resources
link to my screen shots ---