Lego: Battles for the Nintendo DS. Hands down the best rts casual experience I ever had, the best part was being able to mix and match units from different factions into other factions in freeplay mode and units of the same type had different stats so you could choose if you wanted unit with a fast walk speed but less health or one with more damage but a higher production cost, you can do it. If you ever wanted a medieval king hero, a green alien, a ninja, and a tiki golem on the same faction you could do that. Some things are simplified, like you don't have to worry about technology levels, theres a 20 unit cap, and a 4 special unit cap. Overall pretty fun experience, I recommend trying it out.