This is a video game like any other video game, saying that it's no "real" game is nothing more than a veiled insult. You should explain the difference, then you can start insulting.
There's no denying that there's a difference between this and (something like) Civilization. It won't hurt anyone to recognize that this is a completely different sort of game, so long as we don't jump to the conclusion that that's a bad thing.
There's certainly room for this sort of thing, just as there's room for horror flicks in a world with Citizen Kane. There absolutely is: they are entirely different products. I'm not going to play this when I want a thinking sort of game, and I'm not going to play Civilization when I only have fifteen minutes.
A "real" game like you say costs around 40$. It is a very well known gameplay (RTS,FPS,RPG,MMORPG,etc.) but in different clothing. You might play with it for 2-3 months.
Slice HD is a unique gameply, a new experience. You will have a heck lot of fun playing it because it is something fresh that you interact with. I may not be an iPad fan, but the thing is that your 1 month with this whole new game and experience only costs 3$.
For 40$ you can buy multiple amazing games with new dynamics while supporting some indie developpers. It sure wont replace those "big game" but for the price and the fun, it can't be matched!
Also, I can totally see you taking this out when you have friends over and passing it around, making this more of a true "game" (where there is social interaction) than something like "Civilization".
I did not deny that there is a difference. All I was saying is that this is also a real game. (I also think that more complex games are possible on tablets. Carcasonne is more fun on a tablet than on a computer, for example.)
There's certainly room for this sort of thing, just as there's room for horror flicks in a world with Citizen Kane. There absolutely is: they are entirely different products. I'm not going to play this when I want a thinking sort of game, and I'm not going to play Civilization when I only have fifteen minutes.