I am going to assume since you were so quick to write a scathing review you actually know how Android works and understand also how to enable developer options and how to select the graphics driver in use by each application?
I am purposely being rhetorical, because instead of asking for assistance here or asking for how things may be improved, you just jumped directly to crapping on a new product which you knew going in was an Alpha / Beta product – this is why it was promoted and supported on Indiegogo – they know there is more to be done and this is why you got to purchase what would be a $200 phone for $100 in the campaign.
That said, if you enable developer options on the phone, there is then a subsection of ‘Developer Options’ called ‘Game Driver Preferences’ and the Terracube 2e is provided with two different driver options – the default system graphics driver and then a ‘Game Driver’. I would suggest trying to change the driver for your specific games and see if this help improve performance some.
Additionally, if you haven’t already, you should check out the Duraspeed option, so you are sure that when running your games it isn’t also running a bunch of apps in the background. Google services is quite a pig of resources and when left unchecked will use a good portion of the CPU them selves for updates / notifications, using Duraspeed allows you to limit which apps will be able to run actively in the background.
Finally, you should re-set your expectations for this hardware – This isn’t being made by Motorola or Samsung and isn’t a $300.00-$500.00 phone MSRP like some of the ones you mentioned, so you should set your expectations appropriate to the hardware you are working with – it’s goal is to be cheap, easily reparable and environmentally friendly – this is also why the screen is only 720p, while those other phones you mentioned in a similar price bracket will also likely have FHD screens on them. Its a completely different product, made with different goals in mind. If you just want a cheap throw away phone for a kid to play games on, go purchase the Coolpad Brisa from Boost Mobile for $80, that is effectively a similar tier phone without all the things that make Terecube 2e unique, such as replaceable battery, repair-ability, 64GB storage, 4Gb of memory, bio-degradable case, etc.
My 2 cents.