I got this game from the site MyPlayCity(.com) but it isn't longer there. It was a game where you are in a mecha and you have to shoot at zombies. The perspective of the game was top-view, like (SNES) Contra game. The first stages were happening in a destroyed city, then it was a forest and now the enemies are giant bugs. The last stages were in a quadrilateral map. Your objective was to defeat all enemies, till it's count reaches zero. You shoot a gatling gun with LMB and special weapons with RMB. You pick up boxes with special weapons like the ones in Metal Slug saga. Last detail, but not least, the soundtrack were noisy rock songs, those where singers are screaming during almost all time.
If I try to seach "Mecha zombie game", i don't find any game like the one i used to play back in the 2010.
Source: https://www.reddit.com/r/oldgames/comments/uk554a/forgot_the_name_of_this_game/