- When you say Adwords for search, you mean google.com and not display right? I see a bunch of what you describe across the display network any would only recommend running white-listed sites if doing the latter as there is much encouragement of fat finger and kids who press anything etc here.
- Are you allowing search partners? Id going google search I would strongly recommend sticking to google only as there is often more dodgy around partners but this is auto included in setup.
- What kind of KW and variance: Again assuming search, who big are your KW lists and negatives? Apologies if asking the obvious but is this consistent via KW?
- Geographic restriction: Have you broken the effect down geographically? This can lead to huge variance, and to a letter extent times your running.
- Are the ads pushy? Google and some people will put a bunch of effort towards you getting higher click through but fight that. You need to stay withing bands but too many ads are for an off the cuff example; 'Amazing game that will blow you away" gets clicks whereas you'll perform better by setting expectation with the boring 'Download and install this game' as your headline type thing... naturally if bots it wont help.
Game install can be tricky, from what I've seen it's competitive and low margin which is a challenging start point.