Space Stacks (Push Gaming) Slot Demo & Review

We talked a little about space in our opening paragraph. However, there is still plenty more to say – I expect we’ll be seeing many more space-themed slots in the next few years because of the development of SpaceX’s Starship and NASA’s Artemis project – if their multi-billion-dollar rocket made of old shuttle parts ever gets off the ground that is. Anyway, other than Space Stacks, do we have any other creative slots to tell you about that differ from the norm in this niche? Of course, we do; we’re the experts, after all, so go try out Space Donkey from Nolimit City and the totally unique Reapers from Print Studios.

On to the pays section next, and oh my, we are about to have fun with the paytable, too, aren’t we? This game uses ten rows and ten columns, but you need to place a bet on each column to win anything that lands on it. This is a complex setup that can get really expensive if you want to make the biggest prizes worth any real money; take the “MAX” instant prize block, for example, which is worth 5,000x your bet, but if your bet is only a penny, you’ll only be winning €50.00. Interestingly, all the prize blocks have different RTPs, too – the “MAX” block has a 96.07% RTP, for example, while the lower-paying blocks steadily increase higher RTPs.

Fancy a bit more confusion? You might assume that the “50” instant prize block would pay you 50x your bet, yet the paytable states that its “minimum” payout is 50x, whilst its average payout is 65.026x… and the RTP is 96.13%. The “10” instant prize block has an average payout of 13.706x and a 96.22% RTP. The weirdness continues right the way down the list, and there are even two different prize blocks labelled with a “2”, and these have average payouts of 2.759x (RTP 96.35%) and 2.457x (RTP 96.39%). I know that they say space is hard and everything, but come on, that doesn’t mean that space slots must be hard to understand… does it?

At the start of each spin, you can choose from various casino chips to wager on each of the ten different symbol types. For example, you can bet up to €10.00 on the “MAX” instant prize block, up to €20.00 on the Astro, Flip, and Apex bonus blocks, and then up to €100.00 on each of the lower-paying instant prize blocks. This means you can bet as low as €0.10 on a round if you wish – although doing so is probably not worth the trouble – or as high as €670.00 per round (!!!) if you want to max bet on every possible option.

After selecting your bets on the initial screen, a ten-by-ten playfield is displayed with each of the symbols you have bet on horizontally across the top of the screen. After this, several drop sequences will commence where blocks fall onto the playfield from the top, filling up each of the ten-high columns. The first column(s) to reach full capacity will award a win.

Instant Prize Blocks

There are seven instant prize columns with payouts ranging between 2x and 50x, or 5,000x for the single “MAX” instant prize block. These are the most common columns that will fill up, whilst the three bonus columns are much less likely to fill up to capacity.

You can think of this setup as being analogous to the odds of hitting scatter symbols in a regular slot, with the exception that there are no “dead spins” in Space Stacks – you will always win something. However, more often than not, it will be less than the wager you have made to play the current round. The feature blocks are much more exciting, so let’s move on to those now.

There are three feature block columns labelled “ASTRO”, “FLIP”, and “APEX”. The average payouts for these columns are 34.232x, 64.143x, and 299.335x, respectively. The corresponding RTP numbers stated on the paytable are 96.19%, 96.17%, and 96.09%, suggesting that the Astro feature should have superior returns to the Flip feature, whilst the Flip feature should pay more than the Apex feature.

My own results did not tally with the above assumptions; however – whilst RTP is undoubtedly an important factor in determining the value and potential of a feature, it should always be considered as a guideline only. But just what are these features anyway? Let’s find out:

Astro Feature

Fill up the ASTRO feature column, and you will soon find yourself looking at the ASTRO wheel – this 32-segment disc contains numerous cash prizes, bet multipliers, and the dreaded “collect” segment. The thing is, the paytable seems to suggest that there is only one collect segment when the truth of the matter is that there are just as many collect segments as there are valuable segments.

Flip Feature

So, the ASTRO feature had the highest RTP of the trio, yet playing it turned out to be disappointing. What about the FLIP feature, then?

If you successfully fill the column corresponding to this feature, you will be presented with a 6×6 grid of purple squares. Underneath these purple tiles lurk all kinds of cash prizes and several “rocket” symbols, which are undoubtedly your preferred target when picking squares from this grid. You only get three chances to uncover a prize from underneath a purple tile; however, if you find a rocket, your remaining picks will not be reduced.

The first time you find a rocket symbol, your current winnings will be multiplied by 2x. Find another rocket, and your multiplier will increase to 5x. You’ll need a miracle to locate all four rockets hidden on the grid. Still, if you find the third and fourth rocket symbols, congratulations – your multiplier now increases to 10x or 100x, respectively.

Apex Feature

Finally, let’s talk about the APEX feature—this one has the lowest RTP of the three, yet my own experience suggests that this is where the game’s biggest wins can be found. Go figure! The feature begins with an enhancement stage that will boost the value of each of the game’s symbols by either 2x, 3x, 4x, 5x, 6x, 7x, 8x, 10x, 15x, or even 20x.

Next, you will be presented with a new grid format which contains only the six instant prize blocks – yes, I did say six, as the MEGA block is missing from this bonus round for some reason. Talk about a cop out! The feature will progress with several free drops of symbols, and each time a column is filled to the top, you will win its associated prize, multiplied by the value achieved during the enhancement stage.

Once two columns have been successfully filled, the bonus round will switch into a typical three-spin format, where you must land at least one new useful symbol on each drop to avoid losing a life. Lose three lives in a row, and the feature will end. If you are lucky, however, you may manage to fill all six columns e before running out of lives; I achieved this twice during the time I spent testing this game – roughly two hours – suggesting that it isn’t all that hard to achieve.