Pretty gun game! Personally in my runs I found the upgrades unnecessary since the units were so strong already. It was kinda weird that it said level 1 when is seems there is only one level? I haven't played it but this game seems very similar to the Battle Cats which is a pretty fun format for a game. I found myself waiting for like 30-40 seconds with an army of guys for the boss but he just instantly kills them anyways so there wasn't really a need for me to wait. the boss just spawning once you got to the door would have had the same effect. I wish there was difficulty modes so I could try to be strategic rather than hitting the buttons once I had money. The environment/character models and animation were my favorite part by far but the UI kinda detracts from it because there is so much going and its art style is different is each part. Overall a really good game though!