I bought it on sale for me and two friends of mine for a total of less then 5€ and we have collectively sunken over 160 hours into this game. I love it for the variation you can have in this game that seems so 1 dimensional, with diffrent heros, towers, placements and upgrades completely new strats can be explored. The coop mode actually requires some coordination so if you don't wanna use the ingame emotes to communicate i would recommend playing this game with friends. There is microtransactions but from what i saw all the things you can pay for are also buyable with the non pay currency so there isn't much insentive to buy them except if you're impatient.
My overall rating: "Monki/10"